Method for transmitting/receiving emergency information in wireless communication system supporting machine type communication, and device therefor

ABSTRACT

Presented in the present specification are a method for transmitting/receiving emergency information in a wireless communication system supporting machine type communication, and a device therefor. Particularly, the method performed by a terminal can comprise the steps of: receiving, from a base station, a system information block (SIB) including scheduling information about emergency information; receiving, from the base station, configuration information about the search space; receiving, from the base station, downlink control information (DCI) for the notification of the emergency information in the search space; and receiving, from the base station, the emergency information on the basis of the DCI and the scheduling information.

TECHNICAL FIELD

The present disclosure relates to a wireless communication systemsupporting machine type communication (MTC), and particularly, to amethod for transmitting and receiving emergency information and anapparatus therefor.

BACKGROUND ART

In a wireless communication system, mobile communication systems havebeen developed to provide voice services while ensuring activity andmobility of users. However, coverage of mobile communication systems hasbeen extended to include data services, as well as voice services,resulting in an explosive increase in traffic and shortage of resources.To meet the demands of users expecting relatively high speed services,an advanced mobile communication system is required.

Requirements of a next-generation mobile communication system includeaccommodation of increased amounts of data traffic, a significantincrease in a transfer rate per user terminal, accommodation ofconsiderably increased number of connection devices, very low end-to-endlatency, and high energy efficiency. To this end, there have beenresearched various technologies such as dual connectivity, massivemultiple input multiple output (MIMO), in-band full duplex,non-orthogonal multiple access (NOMA), super wideband, devicenetworking, and the like.

DISCLOSURE Technical Problem

An embodiment of the present disclosure provides a method for allowing aUE which operates a coverage enhancement (CE) mode in an RRC connectionstate to efficiently receive emergency information and an apparatustherefor.

Furthermore, an embodiment of the present disclosure provides a methodfor allowing a format of Downlink Control Information (DCI) fornotifying emergency information to have the same format as a DCI format(e.g., DCI format 6-1A and DCI format 6-1B) for scheduling a PhysicalDownlink Control Channel (PDCCH) associated with MTC, and an apparatustherefor.

Furthermore, an embodiment of the present disclosure provides a methodfor allowing DCI for notifying emergency information to have a sizeexcluding information added by Radio Resource Control (RRC)configuration information in a DCI format for scheduling a PDCCHassociated with MTC.

Technical objects to be achieved in the disclosure are not limited tothe above-described technical objects, and other technical objects notdescribed above may be evidently understood by a person having ordinaryskill in the art to which the disclosure pertains from the followingdescription.

Technical Solution

In an aspect, a user equipment (UE) receiving emergency information in awireless communication system supporting Machine Type Communication(MTC) is provided. A method performed by a UE may include: receiving,from a base station (BS), a System Information Block (SIB) includingscheduling information for the emergency information; receiving, fromthe BS, configuration information for a search space; receiving, fromthe BS, Downlink Control Information (DCI) for notification of theemergency information in the search space; and receiving, from the BS,the emergency information based on the DCI and the schedulinginformation, and a format of the DCI may be the same as a DCI format forscheduling a Physical Downlink Shared Channel (PDSCH) related to theMTC, and the DCI may have a size excluding information added by RadioResource Control (RRC) configuration information in the DCI format.

Furthermore, in the method of the present disclosure, the DCI format maybe DCI format 6-1A or DCI format 6-1B.

Furthermore, in the method of the present disclosure, based on theformat of the DCI being the DCI format 6-1A, the size of the DCI may bethe same as the DCI of the DCI format 6-1A mapped to a common searchspace.

Furthermore, in the method of the present disclosure, based on the DCIbeing the DCI format 6-1A, the UE may be a UE which operates in CoverageEnhancement (CE) mode A, and based on the DCI being the DCI format 6-1B,the UE may be a UE which operates in CE mode B.

Furthermore, in the method of the present disclosure, the search spacemay be a type 0-MTC Physical Downlink Control Channel (MPDCCH) commonsearch space.

Furthermore, the method of the present disclosure may further includereceiving, from the BS, a Master Information Block (MIB) includingscheduling information for the SIB.

Furthermore, in the method of the present disclosure, the DCI fornotification of the emergency information may be CRC-scrambled by aSystem Information (SI)-Radio Network Temporary Identifier (RNTI).

Furthermore, in the method of the present disclosure, the DCI fornotification of the emergency information may be received through an MTCPhysical Downlink Control Channel (PDCCH).

Furthermore, in the method of the present disclosure, the UE may operatein an RRC connection state.

In another aspect, provided is a user equipment (UE) receiving emergencyinformation in a wireless communication system supporting Machine TypeCommunication (MTC), which includes: one or more transceivers; one ormore processors; and one or more memories functionally connected to theone or more processors and storing instructions for performingoperations, and the operations may include: receiving, from a basestation (BS), a system information block (SIB) including schedulinginformation for the emergency information; receiving, from the BS,configuration information for a search space; receiving, from the BS,Downlink Control Information (DCI) for notification of the emergencyinformation in the search space; and receiving, from the BS, theemergency information based on the DCI and the scheduling information,and a format of the DCI may be the same as a DCI format for scheduling aPhysical Downlink Shared Channel (PDSCH) related to the MTC, and the DCImay have a size excluding information added by Radio Resource Control(RRC) configuration information in the DCI format.

Furthermore, in yet another aspect in the present disclosure, a methodfor transmitting emergency information in a wireless communicationsystem supporting Machine Type Communication (MTC) is provided. A methodperformed by a base station (BS) may include: transmitting, to a userequipment (UE), a System Information Block (SIB) including schedulinginformation for the emergency information; transmitting, to the UE,configuration information for a search space; transmitting, to the UE,Downlink Control Information (DCI) for notification of the emergencyinformation in the search space; and transmitting, to the UE, theemergency information based on the DCI and the scheduling information,and a format of the DCI may be the same as a DCI format for scheduling aPhysical Downlink Shared Channel (PDSCH) related to the MTC, and the DCImay have a size excluding information added by Radio Resource Control(RRC) configuration information in the DCI format.

Furthermore, in the method of the present disclosure, For example, theDCI format may be DCI format 6-1A or DCI format 6-1B.

Furthermore, in the method of the present disclosure, based on theformat of the DCI being the DCI format 6-1A, the size of the DCI may bethe same as the DCI of the DCI format 6-1A mapped to a common searchspace.

Furthermore, in the method of the present disclosure, based on the DCIbeing the DCI format 6-1A, the UE may be a UE which operates in CoverageEnhancement (CE) mode A and based on the DCI being the DCI format 6-1B,the UE may be a UE which operates in CE mode B.

Furthermore, in the method of the present disclosure, the search spacemay be a type 0-MTC Physical Downlink Control Channel (MPDCCH) commonsearch space.

Furthermore, the method of the present disclosure may further includetransmitting, to the UE, a Master Information Block (MIB) includingscheduling information for the SIB.

Furthermore, in the method of the present disclosure, the DCI fornotifying the emergency information may be CRC-scrambled by a SystemInformation (SI)-Radio Network Temporary Identifier (RNTI).

Furthermore, in the method of the present disclosure, the DCI fornotification of the emergency information may be received through an MTCPhysical Downlink Control Channel (PDCCH).

Furthermore, in the method of the present disclosure, the UE may operatein an RRC connection state.

Further, in still yet another aspect, provided is a base station (BS)transmitting emergency information in a wireless communication systemsupporting Machine Type Communication (MTC), which includes: one or moretransceivers; one or more processors; and one or more memoriesfunctionally connected to the one or more processors and storinginstructions for performing operations, and the operations may include:transmitting, to a user equipment (UE), a System Information Block (SIB)including scheduling information for the emergency information;transmitting, to the UE, configuration information for a search space;transmitting, to the UE, Downlink Control Information (DCI) fornotification of the emergency information in the search space; andtransmitting, to the UE, the emergency information based on the DCI andthe scheduling information, a format of the DCI may be the same as a DCIformat for scheduling a Physical Downlink Shared Channel (PDSCH) relatedto the MTC, and the DCI may have a size excluding information added byRadio Resource Control (RRC) configuration information in the DCIformat.

Furthermore, in still yet another aspect, in an apparatus comprising:

one or more memories and one or more processors functionally connectedto the one or more memories, the one or more processors may beconfigured for the apparatus to receive, from a base station (BS), asystem information block (SIB) including scheduling information foremergency information, receive, from the BS, configuration informationfor a search space, receive, from the BS, Downlink Control Information(DCI) for notification of the emergency information in the search space,and receive, from the BS, the emergency information based on the DCI andthe scheduling information, a format of the DCI may be the same as a DCIformat for scheduling a Physical Downlink Shared Channel (PDSCH) relatedto the MTC, and the DCI may have a size excluding information added byRadio Resource Control (RRC) configuration information in the DCIformat.

Furthermore, in still yet another aspect, in a non-transitory computerreadable medium (CRM) storing one or more instructions, one or moreinstructions executable by one or more processors may control a userequipment (UE) to receive, from a BS, a System Information Block (SIB)including scheduling information for emergency information, receive,from the BS, configuration information for a search space, receive, fromthe BS, Downlink Control Information (DCI) for notification of theemergency information in the search space, and receive, from the BS, theemergency information based on the DCI and the scheduling information, aformat of the DCI may be the same as a DCI format for scheduling aPhysical Downlink Shared Channel (PDSCH) related to the MTC, and the DCImay have a size excluding information added by Radio Resource Control(RRC) configuration information in the DCI format.

Advantageous Effects

According to the present disclosure, there is an effect that a UE whichoperates a coverage enhancement (CE) mode in an RRC connection stateefficiently receives emergency information.

Furthermore, according to the present disclosure, there is an effectthat a format of Downlink Control Information (DCI) for notifyingemergency information has the same format as a DCI format (e.g., DCIformat 6-1A and DCI format 6-1B) for scheduling a Physical DownlinkControl Channel (PDCCH) associated with MTC, thereby reducing ascheduling burden of a BS and increasing downlink transmissionefficiency.

Furthermore, according to the present disclosure, there is an effectthat DCI for notifying emergency information has a size excludinginformation added by Radio Resource Control (RRC) configurationinformation in a DCI format for scheduling a PDCCH associated with MTC,thereby improving complexity and overhead of blind decoding.

Furthermore, according to the present disclosure, there is an effectthat a low-latency and high-reliability wireless communication systemcan be implemented.

Effects which may be obtained in the disclosure are not limited to theabove-described effects, and other technical effects not described abovemay be evidently understood by a person having ordinary skill in the artto which the disclosure pertains from the following description.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and constitute a part of the detaileddescription, illustrate embodiments of the disclosure and together withthe description serve to explain the principle of the disclosure.

FIG. 1 illustrates physical channels and general signal transmissionused in a 3GPP system.

FIG. 2 illustrates the structure of a radio frame in a wirelesscommunication system to which the disclosure may be applied.

FIG. 3 illustrates a resource grid for one downlink slot in a wirelesscommunication system to which the disclosure may be applied.

FIG. 4 illustrates the structure of a downlink subframe in a wirelesscommunication system to which the disclosure may be applied.

FIG. 5 illustrates the structure of an uplink subframe in a wirelesscommunication system to which the disclosure may be applied.

FIG. 6 illustrates an example of an overall structure of a NR system towhich a method proposed in the disclosure may be applied.

FIG. 7 illustrates a relation between an uplink frame and a downlinkframe in a wireless communication system to which a method proposed inthe disclosure may be applied.

FIG. 8 illustrates an example of a frame structure in a NR system.

FIG. 9 illustrates an example of a resource grid supported in a wirelesscommunication system to which a method proposed in the disclosure may beapplied.

FIG. 10 illustrates examples of a resource grid per antenna port andnumerology to which a method proposed in the disclosure may be applied.

FIG. 11 illustrates an example of a self-contained structure to which amethod proposed in the disclosure may be applied.

FIG. 12 illustrates MTC.

FIG. 13 illustrates physical channels and general signal transmissionused in MTC.

FIG. 14 illustrates cell coverage enhancement in MTC.

FIG. 15 illustrates a signal band for MTC.

FIG. 16 illustrates scheduling in legacy LTE and MTC.

FIG. 17 illustrates physical channels used in NB-IoT and general signaltransmission using the physical channels.

FIG. 18 illustrates a frame structure when a subframe spacing is 15 kHz.

FIG. 19 illustrates a frame structure when a subframe spacing is 3.75kHz.

FIG. 20 illustrates three operation modes of NB-IoT.

FIG. 21 illustrates a layout of an in-band anchor carrier at an LTEbandwidth of 10 MHz.

FIG. 22 illustrates transmission of an NB-IoT downlink physicalchannel/signal in an FDD LTE system.

FIG. 23 illustrates an NPUSCH format.

FIG. 24 illustrates an operation when multi-carriers are configured inFDD NB-IoT.

FIG. 25 is a flowchart for describing an operation method of a UEproposed in the present disclosure.

FIG. 26 is a flowchart for describing an operation method of a BSproposed in the present disclosure.

FIG. 27 illustrates a communication system 10 applied to the presentdisclosure.

FIG. 28 illustrates a wireless device which may be applied to thepresent disclosure.

FIG. 29 illustrates a signal processing circuit for a transmit signal.

FIG. 30 illustrates another example of a wireless device applied to thepresent disclosure.

FIG. 31 illustrates a portable device applied to the present disclosure.

MODE FOR INVENTION

Hereafter, preferred embodiments of the disclosure will be described indetail with reference to the accompanying drawings. A detaileddescription to be disclosed hereinafter together with the accompanyingdrawing is to describe embodiments of the disclosure and not to describea unique embodiment for carrying out the disclosure. The detaileddescription below includes details in order to provide a completeunderstanding. However, those skilled in the art know that thedisclosure can be carried out without the details.

In some cases, in order to prevent a concept of the disclosure frombeing ambiguous, known structures and devices may be omitted or may beillustrated in a block diagram format based on core function of eachstructure and device.

In the disclosure, a base station means a terminal node of a networkdirectly performing communication with a terminal. In the presentdocument, specific operations described to be performed by the basestation may be performed by an upper node of the base station in somecases. That is, it is apparent that in the network constituted bymultiple network nodes including the base station, various operationsperformed for communication with the terminal may be performed by thebase station or other network nodes other than the base station. A basestation (BS) may be generally substituted with terms such as a fixedstation, Node B, evolved-NodeB (eNB), a base transceiver system (BTS),an access point (AP), and the like. Further, a ‘terminal’ may be fixedor movable and be substituted with terms such as user equipment (UE), amobile station (MS), a user terminal (UT), a mobile subscriber station(MSS), a subscriber station (SS), an advanced mobile station (AMS), awireless terminal (WT), a Machine-Type Communication (MTC) device, aMachine-to-Machine (M2M) device, a Device-to-Device (D2D) device, andthe like.

Hereinafter, a downlink means communication from the base station to theterminal and an uplink means communication from the terminal to the basestation. In the downlink, a transmitter may be a part of the basestation and a receiver may be a part of the terminal. In the uplink, thetransmitter may be a part of the terminal and the receiver may be a partof the base station.

Specific terms used in the following description are provided to helpappreciating the disclosure and the use of the specific terms may bemodified into other forms within the scope without departing from thetechnical spirit of the disclosure.

The following technology may be used in various wireless access systems,such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier-FDMA(SC-FDMA), non-orthogonal multiple access (NOMA), and the like. The CDMAmay be implemented by radio technology universal terrestrial radioaccess (UTRA) or CDMA2000. The TDMA may be implemented by radiotechnology such as Global System for mobile communications (GSM)/generalpacket radio service (GPRS)/enhanced data rates for GSM evolution(EDGE). The OFDMA may be implemented as radio technology such as IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA),and the like. The UTRA is a part of a universal mobile telecommunicationsystem (UMTS). 3rd generation partnership project (3GPP) long termevolution (LTE) as a part of an evolved UMTS (E-UMTS) using evolved-UMTSterrestrial radio access (E-UTRA) adopts the OFDMA in a downlink and theSC-FDMA in an uplink. LTE-advanced (A) is an evolution of the 3GPP LTE.

Embodiments of the present disclosure may be supported by standarddocuments disclosed in at least one of wireless access systems IEEE 802,3GPP, and 3GPP2. That is, steps or portions of the embodiments of thepresent disclosure which are not described in order to clearlyillustrate the technical spirit of the present disclosure may besupported by the documents. Further, all terms disclosed in the documentmay be described by the standard document.

For clarity of description, a 3GPP LTE/LTE-A/NR system is mainlydescribed, but the technical features of the present disclosure are notlimited thereto.

Physical Channel and General Signal Transmission

FIG. 1 illustrates physical channels and general signal transmissionused in a 3GPP system. In the wireless communication system, the UEreceives information from the BS through Downlink (DL) and the UEtransmits information from the BS through Uplink (UL). The informationwhich the BS and the UE transmit and receive includes data and variouscontrol information and there are various physical channels according toa type/use of the information which the BS and the UE transmit andreceive.

When the UE is powered on or newly enters a cell, the UE performs aninitial cell search operation such as synchronizing with the BS (S11).To this end, the UE may receive a Primary Synchronization Signal (PSS)and a (Secondary Synchronization Signal (SSS) from the BS andsynchronize with the BS and acquire information such as a cell ID or thelike. Thereafter, the UE may receive a Physical Broadcast Channel (PBCH)from the BS and acquire in-cell broadcast information. Meanwhile, the UEreceives a Downlink Reference Signal (DL RS) in an initial cell searchstep to check a downlink channel status.

A UE that completes the initial cell search receives a Physical DownlinkControl Channel (PDCCH) and a Physical Downlink Control Channel (PDSCH)according to information loaded on the PDCCH to acquire more specificsystem information (S12).

Meanwhile, when there is no radio resource first accessing the BS or forsignal transmission, the UE may perform a Random Access Procedure (RACH)to the BS (S13 to S16). To this end, the UE may transmit a specificsequence to a preamble through a Physical Random Access Channel (PRACH)(S13 and S15) and receive a response message (Random Access Response(RAR) message) for the preamble through the PDCCH and a correspondingPDSCH. In the case of a contention based RACH, a Contention ResolutionProcedure may be additionally performed (S16).

The UE that performs the above procedure may then perform PDCCH/PDSCHreception (S17) and Physical Uplink Shared Channel (PUSCH)/PhysicalUplink Control Channel (PUCCH) transmission (S18) as a generaluplink/downlink signal transmission procedure. In particular, the UE mayreceive Downlink Control Information (DCI) through the PDCCH. Here, theDCI may include control information such as resource allocationinformation for the UE and formats may be differently applied accordingto a use purpose.

Meanwhile, the control information which the UE transmits to the BSthrough the uplink or the UE receives from the BS may include adownlink/uplink ACK/NACK signal, a Channel Quality Indicator (CQI), aPrecoding Matrix Index (PMI), a Rank Indicator (RI), and the like. TheUE may transmit the control information such as the CQI/PMI/RI, etc.,through the PUSCH and/or PUCCH.

Overview of LTE System

FIG. 2 illustrates the structure of a radio frame in a wirelesscommunication system to which the disclosure may be applied.

A 3GPP LTE/LTE-A supports radio frame structure type 1 applicable tofrequency division duplex (FDD) and radio frame structure type 2applicable to time division duplex (TDD).

In FIG. 2, the size of the radio frame in the time domain is representedby a multiple of a time unit of T_s=1/(15000*2048). The downlink anduplink transmissions are configured by a radio frame having an intervalof T_f=307200*T_s=10 ms.

FIG. 2(a) illustrates the structure of radio frame type 1. Radio frametype 1 may be applied to both full duplex and half duplex FDDs.

The radio frame is constituted by 10 subframes. One radio frame isconstituted by 20 slots having a length of T_slot=15360*T_s=0.5 ms andindexes of 0 to 19 are granted to each slot. One subframe is constitutedby two consecutive slots in the time domain and subframe i isconstituted by slot 2i and slot 2i+1. A time required for transmittingone subframe is referred to as a transmission time interval (TTI). Forexample, a length of one subframe may be 1 ms and the length of one slotmay be 0.5 ms.

In the FDD, the uplink transmission and the downlink transmission areclassified in the frequency domain. There is no limit in the full duplexFDD, while in a half duplex FDD operation, the UE may not performtransmission and reception simultaneously.

One slot includes a plurality of orthogonal frequency divisionmultiplexing (OFDM) symbols in the time domain and includes multipleresource blocks (RBs) in the frequency domain. Since the 3GPP LTE usesOFDMA in the downlink, the OFDM symbol is intended to represent onesymbol period. The OFDM symbol may be referred to as one SC-FDMA symbolor symbol period. A resource block as a resource allocation unitincludes a plurality of consecutive subcarriers in one slot.

The subframe may be defined as one or more slots as below according to asubcarrier spacing (SCS).

-   -   In the case of SCS=7.5 kHz or 15 kHz, subframe #i is defined as        two 0.5 ms slots #2i and #2i+1 (i=0 to 9).    -   In the case of SCS=1.25 kHz, subframe #i is defined as one 1 ms        slot #2i.    -   In the case of SCS=15 kHz, subframe #i may be defined as six        subslots as shown in Table A1.

Table 1 shows a subslot configuration in the subframe (normal CP).

TABLE 1 Subslot number 0 1 2 3 4 5 Slot number 2i 2i + 1 Uplink subslotpattern 0, 1, 2 3, 4 5, 6 0, 1 2, 3 4, 5, 6 (Symbol number) Downlinksubslot 0, 1, 2 3, 4 5, 6 0, 1 2, 3 4, 5, 6 pattern 1 (Symbol number)Downlink subslot 0, 1 2, 3, 4 5, 6 0, 1 2, 3 4, 5, 6 pattern 2 (Symbolnumber)

FIG. 2(b) illustrates frame structure type 2.

Radio frame type 2 is constituted by two half frames each having alength of 153600*T_s=5 ms. Each half frame is constituted by 5 subframeshaving a length of 30720*T_s=1 ms.

In frame structure type 2 of the TDD system, an uplink-downlinkconfiguration is a rule indicating whether the uplink and the downlinkare assigned (or reserved) for all subframes.

Table 2 shows an uplink-downlink configuration.

TABLE 2 Downlink- Uplink- to-Uplink Downlink Switch- config- pointSubframe number uration periodicity 0 1 2 3 4 5 6 7 8 9 0  5 ms D S U UU D S U U U 1  5 ms D S U U D D S U U D 2  5 ms D S U D D D S U D D 3 10ms D S U U U D D D D D 4 10 ms D S U U D D D D D D 5 10 ms D S U D D D DD D D 6  5 ms D S U U U D S U U D

Referring to Table 2, for each subframe of the radio frame, ‘D’ denotesa subframe for the downlink transmission, ‘U’ denotes a subframe for theuplink transmission, ‘S’ denotes a special subframe constituted by threefields, i.e., a downlink pilot time slot (DwPTS), a guard period (GP),and an uplink pilot time slot (UpPTS). The DwPTS is used for initialcell search, synchronization, or channel estimation in the UE. The UpPTSis used to match the channel estimation at the base station and uplinktransmission synchronization of the UE. The GP is a period foreliminating interference caused in the uplink due to a multi-path delayof a downlink signal between the uplink and the downlink.

Each subframe i is constituted by slot 2i and slot 2i+1 each having alength of T_slot=15360*T_s=0.5 ms.

The uplink-downlink configuration may be divided into 7 types andlocations and/or the numbers of downlink subframes, special subframes,and uplink subframes vary for each configuration.

A point when the downlink is changed to the uplink or a point when theuplink is switched to the downlink is referred to as a switching point.Switch-point periodicity means a period in which an aspect in which theuplink subframe and the downlink subframe are switched is similarlyrepeated and both 5 ms and 10 ms are supported. When thedownlink-downlink switch-point periodicity is 5 ms, the special subframeS exists for each half-frame and when the downlink-uplink switch-pointperiodicity is 5 ms, the special subframe S exists only in a firsthalf-frame.

In all configurations, subframes #0 and #5 and the DwPTS are periodsonly for the downlink transmission. The UpPTS and the subframe and asubframe immediately following the subframe are always periods for theuplink transmission.

The uplink-downlink configuration as system information may be known byboth the base station and the UE. The base station transmits only anindex of configuration information whenever the configurationinformation is changed to notify the UE of a change of anuplink-downlink assignment state of the radio frame. Further, theconfiguration information as a kind of downlink control information maybe transmitted through a physical downlink control channel (PDCCH)similar to another scheduling information and as broadcast informationmay be commonly transmitted to all UEs in a cell through a broadcastchannel.

Table 3 shows a configuration (the length of DwPTS/GP/UpPTS) of thespecial subframe.

TABLE 3 Special Normal cyclic prefix in dowlink Extended cyclic prefixin dowlink subframe UpPTS UpPTS config- Normal cyclic Extended cyclicNormal cyclic Extended cyclic uration DwPTS prefix in uplink prefix inuplink DwPTS prefix in uplink prefix in uplink 0  6592 · T_(s) (1 + X) ·2192 · T_(s) (1 + X) · 2560 · T_(s)  7680 · T_(s) (1 + X) · 2192 · T_(s)(1 + X) · 2560 · T_(s) 1 19760 · T_(s) 20480 · T_(s) 2 21952 · T_(s)23040 · T_(s) 3 24344 · T_(s) 25600 · T_(s) 4 26336 · T_(s)  7680 ·T_(s) (2 + X) · 2192 · T_(s) (2 + X) · 2560 · T_(s) 5  6592 · T_(s) (2 +X) · 2192 · T_(s) (2 + X) · 2560 · T_(s) 20480 · T_(s) 6 19760 · T_(s)23040 · T_(s) 7 21952 · T_(s) 12800 · T_(s) 8 24144 · T_(s) — — — 913168 · T_(s) — — — 10 13168 · T_(s) 13152 · T_(s) 12800 · T_(s) — — —

Here, X is configured by a higher layer (e.g., RRC) signal or given as0.

The structure of the radio frame according to the example of FIG. 2 ismerely an example and the number of subcarriers included in the radioframe or the number of slots included in the subframe, and the number ofOFDM symbols included in the slot may be variously changed.

FIG. 3 is a diagram illustrating a resource grid for one downlink slotin the wireless communication system to which the disclosure may beapplied.

Referring to FIG. 3, one downlink slot includes the plurality of OFDMsymbols in the time domain. Herein, it is exemplarily described that onedownlink slot includes 7 OFDM symbols and one resource block includes 12subcarriers in the frequency domain, but the disclosure is not limitedthereto.

Each element on the resource grid is referred to as a resource elementand one resource block includes 12×7 resource elements. The number ofresource blocks included in the downlink slot, NDL is subordinated to adownlink transmission bandwidth.

A structure of the uplink slot may be the same as that of the downlinkslot.

FIG. 4 illustrates the structure of a downlink subframe in the wirelesscommunication system to which the disclosure may be applied.

Referring to FIG. 4, a maximum of three former OFDM symbols in the firstslot of the sub frame is a control region to which control channels areallocated and residual OFDM symbols is a data region to which a physicaldownlink shared channel (PDSCH) is allocated. Examples of the downlinkcontrol channel used in the 3GPP LTE include a physical control formatindicator channel (PCFICH), a Physical Downlink Control Channel (PDCCH),a Physical Hybrid-ARQ Indicator Channel (PHICH), and the like.

The PFCICH is transmitted in the first OFDM symbol of the subframe andtransports information on the number (that is, the size of the controlregion) of OFDM symbols used for transmitting the control channels inthe subframe. The PHICH which is a response channel to the uplinktransports an Acknowledgement (ACK)/Not-Acknowledgement (NACK) signalfor a hybrid automatic repeat request (HARQ). Control informationtransmitted through a PDCCH is referred to as downlink controlinformation (DCI). The downlink control information includes uplinkresource allocation information, downlink resource allocationinformation, or an uplink transmission (Tx) power control command for apredetermined terminal group.

The PDCCH may transport A resource allocation and transmission format(also referred to as a downlink grant) of a downlink shared channel(DL-SCH), resource allocation information (also referred to as an uplinkgrant) of an uplink shared channel (UL-SCH), paging information in apaging channel (PCH), system information in the DL-SCH, resourceallocation for an upper-layer control message such as a random accessresponse transmitted in the PDSCH, an aggregate of transmission powercontrol commands for individual terminals in the predetermined terminalgroup, a voice over IP (VoIP). A plurality of PDCCHs may be transmittedin the control region and the terminal may monitor the plurality ofPDCCHs. The PDCCH is constituted by one or an aggregate of a pluralityof continuous control channel elements (CCEs). The CCE is a logicalallocation wise used to provide a coding rate depending on a state of aradio channel to the PDCCH. The CCEs correspond to a plurality ofresource element groups. A format of the PDCCH and a bit number ofusable PDCCH are determined according to an association between thenumber of CCEs and the coding rate provided by the CCEs.

The base station determines the PDCCH format according to the DCI to betransmitted and attaches a cyclic redundancy check (CRC) to the controlinformation. The CRC is masked with a unique identifier (referred to asa radio network temporary identifier (RNTI)) according to an owner or apurpose of the PDCCH. In the case of a PDCCH for a specific terminal,the unique identifier of the terminal, for example, a cell-RNTI (C-RNTI)may be masked with the CRC. Alternatively, in the case of a PDCCH forthe paging message, a paging indication identifier, for example, the CRCmay be masked with a paging-RNTI (P-RNTI). In the case of a PDCCH forthe system information, in more detail, a system information block(SIB), the CRC may be masked with a system information identifier, thatis, a system information (SI)-RNTI. The CRC may be masked with a randomaccess (RA)-RNTI in order to indicate the random access response whichis a response to transmission of a random access preamble.

An enhanced PDCCH (EPDCCH) carries UE-specific signaling. The EPDCCH islocated in a physical resource block (PRB) that is configured to be UEspecific. In other words, as described above, the PDCCH may betransmitted in up to first three OFDM symbols in a first slot of asubframe, but the EPDCCH may be transmitted in a resource region otherthan the PDCCH. A time (i.e., symbol) at which the EPDCCH starts in thesubframe may be configured to the UE via higher layer signaling (e.g.,RRC signaling).

The EPDCCH may carry a transport format, resource allocation and HARQinformation related to DL-SCH, a transport format, resource allocationand HARQ information related to UL-SCH, resource allocation informationrelated to sidelink shared channel (SL-SCH) and physical sidelinkcontrol channel (PSCCH), etc. Multiple EPDCCHs may be supported, and theUE may monitor a set of EPCCHs.

The EPDCCH may be transmitted using one or more consecutive enhancedCCEs (ECCEs), and the number of ECCEs per EPDCCH may be determined foreach EPDCCH format.

Each ECCE may consist of a plurality of enhanced resource element groups(EREGs). The EREG is used to define mapping of the ECCE to the RE. Thereare 16 EREGs per PRB pair. All REs except the RE carrying the DMRS ineach PRB pair are numbered from 0 to 15 in increasing order of thefrequency and then in increasing order of time.

The UE may monitor a plurality of EPDCCHs. For example, one or twoEPDCCH sets may be configured in one PRB pair in which the UE monitorsEPDCCH transmission.

Different coding rates may be implemented for the EPOCH by combiningdifferent numbers of ECCEs. The EPOCH may use localized transmission ordistributed transmission, and hence, the mapping of ECCE to the RE inthe PRB may vary.

FIG. 5 illustrates the structure of an uplink subframe in the wirelesscommunication system to which the disclosure may be applied.

Referring to FIG. 5, the uplink subframe may be divided into the controlregion and the data region in a frequency domain. A physical uplinkcontrol channel (PUCCH) transporting uplink control information isallocated to the control region. A physical uplink shared channel(PUSCH) transporting user data is allocated to the data region. Oneterminal does not simultaneously transmit the PUCCH and the PUSCH inorder to maintain a single carrier characteristic.

A resource block (RB) pair in the subframe is allocated to the PUCCH forone terminal. RBs included in the RB pair occupy different subcarriersin two slots, respectively. The RB pair allocated to the PUCCHfrequency-hops in a slot boundary.

Overview of NR System

The following disclosure proposed by the disclosure can be applied to a5G NR system (or device) as well as a LTE/LTE-A system (or device).

Communication of the 5G NR system is described below with reference toFIGS. 6 to 11.

The 5G NR system defines enhanced mobile broadband (eMBB), massivemachine type communications (mMTC), ultra-reliable and low latencycommunications (URLLC), and vehicle-to-everything (V2X) based on usagescenario (e.g., service type).

A 5G NR standard is divided into standalone (SA) and non-standalone(NSA) depending on co-existence between a NR system and a LTE system.

The 5G NR system supports various subcarrier spacings and supportsCP-OFDM in the downlink and CP-OFDM and DFT-s-OFDM (SC-OFDM) in theuplink.

Embodiments of the disclosure can be supported by standard documentsdisclosed in at least one of IEEE 802, 3GPP, and 3GPP2 which are thewireless access systems. That is, steps or parts in embodiments of thedisclosure which are not described to clearly show the technical spiritof the disclosure can be supported by the standard documents. Further,all terms disclosed in the disclosure can be described by the standarddocument.

As smartphones and Internet of Things (IoT) terminals spread rapidly, anamount of information exchanged through a communication network isincreasing. Hence, it is necessary to consider an environment (e.g.,enhanced mobile broadband communication) that provides faster servicesto more users than the existing communication system (or existing radioaccess technology) in the next generation wireless access technology.

To this end, a design of a communication system considering machine typecommunication (MTC) that provides services by connecting multipledevices and objects is being discussed. In addition, a design of acommunication system (e.g., ultra-reliable and low latency communication(URLLC) considering a service and/or a terminal sensitive to reliabilityand/or latency of communication is also being discussed.

Hereinafter, in the disclosure, for convenience of description, the nextgeneration radio access technology is referred to as NR (new RAT, radioaccess technology), and a wireless communication system to which the NRis applied is referred to as an NR system.

Definition of NR system related terms

eLTE eNB: The eLTE eNB is the evolution of eNB that supportsconnectivity to EPC and NGC.

gNB: A node which supports the NR as well as connectivity to NGC.

New RAN: A radio access network which supports either NR or E-UTRA orinterfaces with the NGC.

Network slice: A network slice is a network defined by the operatorcustomized to provide an optimized solution for a specific marketscenario which demands specific requirements with end-to-end scope.

Network function: A network function is a logical node within a networkinfrastructure that has well-defined external interfaces andwell-defined functional behavior.

NG-C: A control plane interface used on NG2 reference points between newRAN and NGC.

NG-U: A user plane interface used on NG3 reference points between newRAN and NGC.

Non-standalone NR: A deployment configuration where the gNB requires anLTE eNB as an anchor for control plane connectivity to EPC, or requiresan eLTE eNB as an anchor for control plane connectivity to NGC.

Non-standalone E-UTRA: A deployment configuration where the eLTE eNBrequires a gNB as an anchor for control plane connectivity to NGC.

User plane gateway: A termination point of NG-U interface.

FIG. 6 illustrates an example of an overall structure of a NR system towhich a method proposed in the disclosure may be applied.

Referring to FIG. 6, an NG-RAN consists of gNBs that provide an NG-RAuser plane (new AS sublayer/PDCP/RLC/MAC/PHY) and control plane (RRC)protocol terminations for a user equipment (UE).

The gNBs are interconnected with each other by means of an Xn interface.

The gNBs are also connected to an NGC by means of an NG interface.

More specifically, the gNBs are connected to an access and mobilitymanagement function (AMF) by means of an N2 interface and to a userplane function (UPF) by means of an N3 interface.

The NR supports multiple numerologies (or subcarrier spacing (SCS)) forsupporting various 5G services. For example, when the SCS is 15 kHz, awide area in traditional cellular bands is supported and when the SCS is30 kHz/60 kHz, dense-urban, lower latency, and wider carrier bandwidthare supported, and when the SCS is 60 kHz or higher therethan, abandwidth larger than 24.25 GHz is supported in order to overcome phasenoise.

An NR frequency band is defined as frequency ranges of two types (FR1and FR2). FR1 and FR2 may be configured as shown in Table 4 below.Further, FR2 may mean a millimeter wave (mmW).

TABLE 4 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

New Rat (NR) Numerology and Frame Structure

The NR system may support multiple numerologies. Here, the numerologymay be defined by a subcarrier spacing and cyclic prefix (CP) overhead.In this case, multiple subcarrier spacings may be derived by scaling abasic subcarrier spacing with an integer N (or μ). Further, even if itis assumed that a very low subcarrier spacing is not used at a very highcarrier frequency, the used numerology may be selected independently ofa frequency band.

In addition, in the NR systems, various frame structures depending onmultiple numerologies may be supported.

Hereinafter, Orthogonal Frequency Division Multiplexing (OFDM)numerology and the frame structure which may be considered in the NRsystem will be described.

Multiple OFDM numerologies supported in the NR systems may be defined asshown in Table 5.

TABLE 5 μ Δf = 2^(μ) · 15 [kHz] Cyclic prefix 0 15 Normal 1 30 Normal 260 Normal, Extended 3 120 Normal 4 240 Normal

In respect to the frame structure in the NR system, sizes of variousfields are expressed as a multiple of a time unit ofT_(s)=1/(Δf_(max)·N_(f)). Here, Δf_(max)=480·10³ and N_(f)=4096.Downlink and uplink transmission is configured by a radio frame having asection of T_(f)=(Δf_(max)N_(f)/100)·T_(s)=10 ms. Here, the radio frameis constituted by 10 subframes each having a section ofT_(sf)=(Δf_(max)N_(f)/1000)·T_(s)=1 ms. In this case, one set of framesfor uplink and one set frames for downlink may exist.

FIG. 7 illustrates a relationship between an uplink frame and a downlinkframe in a wireless communication system to which a method proposed inthe present disclosure may be applied.

As illustrated in FIG. 7, transmission of uplink frame number i from theUE should start before the start of the corresponding downlink frame inthe corresponding UE by T_(TA)=N_(TA)T_(s).

For numerology μ, slots are numbered in an increasing number of n_(s)^(μ)∈{0, . . . , N_(subframe) ^(slots,μ)−1} in the subframe and numberedin an increasing order of n_(s,f) ^(μ)∈{0, . . . , N_(frame)^(slots,μ)−1} in the radio frame. One slot is constituted by consecutiveOFDM symbols of N_(symb) ^(μ) and N_(symb) ^(μ) is determined accordingto used numerology and slot configuration. The start of slot n_(s) ^(μ)in the subframe is temporally aligned with the start of THE OFDM symboln_(s) ^(μ)N_(symb) ^(μ) in the same subframe.

All UEs may not simultaneously perform transmission and reception andthis means that all OFDM symbols of a downlink slot or an uplink slotmay not be used.

Table 6 shows the number of OFDM symbols for slot (N_(symb) ^(slot)),the number of slots for each radio frame (N_(slot) ^(frame,μ)), and thenumber of slots for each subframe (N_(slot) ^(subframe,μ)) in the normalCP and Table 7 shows the number of OFDM symbols for each slot, thenumber of slots for each radio frame, and the number of slots for eachsubframe in the extended CP.

TABLE 6 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

TABLE 7 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

FIG. 8 illustrates an example of a frame structure in an NR system. FIG.8 is just for convenience of the description and does not limit thescope of the present disclosure.

In the case of Table 7, as an example of a case where μ=2, that is, acase where the subcarrier spacing is 60 kHz, referring to Table 7, onesubframe may include four slots, and one subframe={1, 2, 4} slotsillustrated in FIG. 8 is an example and the number of slots which mayincluded in one subframe may be defined as in Table 7.

Further, a mini-slot may be constituted by 2, 4, or 7 symbols andconstituted by more or less symbols.

With respect to the physical resource in the NR system, an antenna port,a resource grid, a resource element, a resource block, a carrier part,and the like may be considered.

Hereinafter, the physical resources which may be considered in the NRsystem will be described in detail.

First, with respect to the antenna port, the antenna port is defined sothat a channel in which the symbol on the antenna port is transportedmay be inferred from a channel in which different symbols on the sameantenna port are transported. When a large-scale property of a channelin which a symbol on one antenna port is transported may be interredfrom a channel in which symbols on different antenna ports aretransported, two antenna ports may have a quasi co-located or quasico-location (QC/QCL) relationship. Here, the large-scale propertyincludes at least one of a delay spread, a Doppler spread, a frequencyshift, average received power, and a received timing.

FIG. 9 illustrates an example of a resource grid supported by a wirelesscommunication system to which a method proposed in the presentdisclosure may be applied.

Referring to FIG. 9, it is exemplarily described that the resource gridis constituted by N_(RB) ^(μ)N_(sc) ^(RB) subcarriers on the frequencydomain and one subframe is constituted by 14.2P OFDM symbols, but thepresent disclosure is not limited thereto.

In the NR system, a transmitted signal is described by one or moreresource grids constituted by N_(RB) ^(μ)N_(sc) ^(RB) subcarriers and2^(μ)N_(symb) ^((μ)) OFDM symbols. Here, N_(RB) ^(μ)≤N_(RB) ^(max,μ).The N_(RB) ^(max,μ) represents a maximum transmission bandwidth and thismay also vary between uplink and downlink in addition to numerology.

In this case, as illustrated in FIG. 10, one resource grid may beconfigured for each numerology μ and antenna port p.

FIG. 10 illustrates examples of a resource grid for each antenna portand numerology to which a method proposed in the present disclosure maybe applied.

Each element for resource grids for numerology and antenna port p isreferred to as the resource element and is uniquely identified by indexpair (k,l). Here, k=0, . . . , N_(RB) ^(μ)N_(sc) ^(RB)−1 represents theindex on the frequency domain and l=0, . . . , 2 ^(μ)N_(symb) ^((μ))−1refers to the position of the symbol in the subframe. When the resourceelement is referred in the slot, index pair (k,l) is used. Here, l=0, .. . , N_(symb) ^(μ)−1.

Resource element (k,l) for numerology μ and antenna p corresponds tocomplex value a_(k,l) ^((p,u)). When there is no confusion or when aspecific antenna port or numerology is not specified, indexes p and μmay be dropped. As a result, the complex value may be a_(k,l) ^((p)) ora_(k,l) .

Further the physical resource block is defined by N_(sc) ^(RB)=12consecutive subcarriers on the frequency domain.

Point A may serve as a common reference point of a resource block gridand may be acquired as follows.

-   -   OffsetToPointA for PCell downlink indicates the frequency offset        between the lowest subcarrier of the lowest resource block        superposed with the SS/PBCH block used by the UE for initial        cell selection and point A, and is expressed by resource block        units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHz        subcarrier spacing for FR2; and    -   absoluteFrequencyPointA indicates the frequency-position of        point A expressed as in an absolute radio-frequency channel        number (ARFCN).

Common resource blocks are numbered upwards from 0 in the frequencydomain for subcarrier spacing configuration μ.

A center of subcarrier 0 of common resource block 0 for subcarrierspacing μ coincides with ‘point A’. A resource element (k,l) for commonresource block number n_(CRB) ^(μ) and subcarrier spacing configurationμ may be given as in Equation 1 below.

$\begin{matrix}{n_{CRB}^{\mu} = \left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Here, k may be relatively defined to point A so that k=0 corresponds toa subcarrier centered on point A. Physical resource blocks are numberedfrom 0 to N_(BWP,i) ^(size)−1 in a bandwidth part (BWP) and i representsthe number of the BWP. A relationship between physical resource blockn_(PRB) and common resource block n_(CRB) may be given by Equation 2below.

$\begin{matrix}{n_{CRB} = {n_{PRB} + N_{{BWP},i}^{start}}} & \left\{ {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Here, N_(BWP,i) ^(start) may represent a common resource block in whichthe BWP starts relatively to common resource block 0.

Self-Contained Structure

A time division duplexing (TDD) structure considered in the NR system isa structure in which both uplink (UL) and downlink (DL) are processed inone slot (or subframe). This is to minimize the latency of datatransmission in the TDD system and the structure may be referred to as aself-contained structure or a self-contained slot.

FIG. 11 illustrates one example of a self-contained structure to which amethod proposed in the present disclosure may be applied. FIG. 11 isjust for convenience of the description and does not limit the scope ofthe present disclosure.

Referring to FIG. 11, it is assumed that one transmission unit (e.g.,slot or subframe) is constituted by 14 orthogonal frequency divisionmultiplexing (OFDM) symbols as in legacy LTE.

In FIG. 11, a region 1102 refers to a downlink control region and aregion 1104 refers to an uplink control region. Further, regions (thatis, regions without a separate indication) other than the regions 1102and 1104 may be used for transmitting downlink data or uplink data.

That is, uplink control information and downlink control information maybe transmitted in one self-contained slot. On the contrary, in the caseof data, the uplink data or downlink data may be transmitted in oneself-contained slot.

When the structure illustrated in FIG. 11 is used, in one self-containedslot, downlink transmission and uplink transmission may sequentiallyproceed and transmission of the downlink data and reception of uplinkACK/NACK may be performed.

Consequently, when an error of data transmission occurs, a time requiredfor retransmitting data may be reduced. Therefore, latency associatedwith data transfer may be minimized.

In the self-contained slot structure illustrated in FIG. 11, a time gapfor a process of switching from a transmission mode to a reception modeof a base station (eNodeB, eNB, or gNB) and/or a terminal (userequipment (UE)) or a process of switching from the reception mode to thetransmission mode is required. In association with the time gap, whenthe uplink transmission is performed after the downlink transmission inthe self-contained slot, some OFDM symbol(s) may be configured as aguard period (GP).

Downlink Channel Structure

The BS transmits an associated signal to the UE through a downlinkchannel to be described below and the UE receives the associated signalfrom the BS through the downlink channel to be described below.

Physical Downlink Shared Channel (PDSCH)

The PDSCH transports downlink data (e.g., DL-shared channel transportblock (DL-SCH TB)), and adopts modulation methods such as QuadraturePhase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM), 64QAM, and 256 QAM. A codeword is generated by encoding a TB. The PDSCHmay transport a maximum of 2 codewords. Scrambling and modulationmapping are performed for each codeword and modulation symbols generatedfrom each codeword are mapped to one or more layers (layer mapping).Each layer is mapped to a resource together with a demodulationreference signal (DMRS), generated as an OFDM symbol signal, andtransmitted through a corresponding antenna port.

Physical Downlink Control Channel (PDCCH)

The PDCCH transports downlink control information (DCI) and a QPSKmodulation method is applied. One PDCCH is constituted by 1, 2, 4, 8,and 16 Control Channel Elements (CCEs) according to an Aggregation Level(AL). One CCE is constituted by 6 Resource Element Groups (REGs). OneREG is defined by one OFDM symbol and one (P)RB. The PDCCH istransmitted through a control resource set (CORESET). The CORESET isdefined as a REG set with given numerology (e.g., SCS, CP length, etc.).A plurality of CORESETs for one UE may be overlapped in thetime/frequency domain. The CORESET may be configured through systeminformation (e.g., MIB) or UE-specific higher layer (e.g., RadioResource Control or RRC layer) signaling. Specifically, the number ofRBs and the number of symbols (maximum 3) constituting the CORESET maybe configured by the higher layer signaling.

The UE performs decoding (so-called, blind decoding) for a set of PDCCHcandidates to obtain the DCI transmitted through the PDCCH. The set ofPDCCH candidates decoded by the UE is defined as a PDCCH search spaceset. The search space set may be a common search space or a UE-specificsearch space. The UE may obtain the DCI by monitoring PDCCH candidatesin one or more search space sets configured by the MIB or higher layersignaling. Each CORESET configuration is associated with one or moresearch space sets and each search space set is associated with oneCORESET configuration. One search space set is determined based on thefollowing parameters.

-   -   controlResourceSetId: represents a control resource set        associated with the search space set    -   monitoringSlotPeriodicityAndOffset: represents a PDCCH        monitoring period section (slot unit) and an PDCCH monitoring        section offset (slot unit)    -   monitoringSymbolsWithinSlot: represents a PDCCH monitoring        pattern in the slot for PDCCH monitoring (e.g., represents a        first symbol(s) of a control resource set)    -   nrofCandidates: represents the number of PDCCH candidates (one        value of 0, 1, 2, 3, 4, 5, 6, and 8) for each AL={1, 2, 4, 8,        16}

Table 8 shows a feature for each search space type.

TABLE 8 Type Search Space RNTI Use Case Type0-PDCCH Common SI-RNTI on aprimary cell SIB Decoding Type0A-PDCCH Common SI-RNTI on a primary cellSIB Decoding Type1-PDCCH Common RA-RNTI or TC-RNTI on a primary celllMsg2, Msg4 decoding in RACH Type2-PDCCH Common P-RNTI on a primary cellPaging Decoding Type3-PDCCH Common INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI,TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI(s) UESpecific C-RNTI, or MCS-C-RNTI, or CS-RNTI(s) User specific PDSCHdecoding

Table 9 shows DCI formats transmitted through the PDCCH.

TABLE 9 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used to schedule TB-based (or TB-level) PUSCH, DCIformat 0_1 may be used to schedule TB-based (or TB-level) PUSCH or CodeBlock Group (CBG)-based (or CBG-level) PUSCH. DCI format 1_0 may be usedto schedule TB-based (or TB-level) PDSCH, DCI format 1_1 may be used toschedule TB-based (or TB-level) PDSCH or Code Block Group (CBG)-based(or CBG-level) PDSCH. DCI format 2_0 is used for transferring dynamicslot format information (e.g., dynamic SFI) to the UE and DCI format 2_1is used for transferring downlink pre-emption information to the UE. DCIformat 2_0 and/or DCI format 2_1 may be transferred to UEs in thecorresponding group through group common PDCCH which is PDCCHtransferred to UEs defined as one group.

Uplink Channel Structure

The UE transmits an associated signal to the BS through an uplinkchannel to be described below and the BS receives the associated signalfrom the UE through the uplink channel to be described below.

Physical Uplink Shared Channel (PUSCH)

The PUSCH transports uplink data (e.g., UL-shared channel transportblock (UL-SCH TB) and/or uplink control information (UCI) and istransmitted based on a Cyclic Prefix-Orthogonal Frequency DivisionMultiplexing (CP-OFDM) waveform or a Discrete FourierTransform-spread—Orthogonal Frequency Division Multiplexing (DFT-s-OFDM)waveform. When the PUSCH is transmitted based on the DFT-s-OFDMwaveform, the UE transmits the PUSCH by applying transform precoding. Asan example, when the transform precoding is disable (e.g., transformprecoding is disabled), the UE transmits the PUSCH based on the CP-OFDMwaveform, and when the transform precoding is enabled (e.g., transformprecoding is enabled), the UE may transmit the PUSCH based on theCP-OFDM waveform or the DFT-s-OFDM waveform. PUSCH transmission isdynamically scheduled by the UL grant in the DCI or semi-staticallyscheduled based on higher layer (e.g., RRC) signaling (and/or Layer 1(L1) signaling (e.g., PDCCH)) (configured grant). The PUSCH transmissionmay be performed based on a codebook or a non-codebook.

Physical Uplink Control Channel (PUCCH)

The PUCCH transports uplink control information, HARQ-ACK, and/orscheduling request (SR), and is divided into Short PUCCH and Long PUCCHaccording to a PUCCH transmission length. Table 10 shows PUCCH formats.

TABLE 10 Length in OFDM PUCCH symbols Number format N_(symb) ^(PUCCH) ofbits Usage Etc 0 1-2  ≤2 HARQ, SR Sequence selection 1 4-14 ≤2 HARQ,[SR] Sequence modulation 2 1-2  >2 HARQ, CSI, [SR] CP-OFDM 3 4-14 >2HARQ, CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4 4-14 >2 HARD, CSI,[SR] DFT-s-OFDM (Pre DFT OCC)

PUCCH format 0 transports the UCI with a maximum size of 2 bits and ismapped and transmitted based on a sequence. Specifically, the UEtransmits specific UCI to the BS by transmitting one of a plurality ofsequences through the PUCCH which is PUCCH format 0. The UE transmitsthe PUCCH which is PUCCH format 0 within a PUCCH resource forcorresponding SR configuration only when transmitting a positive SR.

PUCCH format 1 transports the UCI having the maximum size of 2 bits andthe modulation signal is spread by an orthogonal cover code (OCC)(configured differently depending on whether or not frequency hopping)in the time domain. The DMRS is transmitted in a symbol in which themodulation symbol is not transmitted (that is, time division multiplexed(TDMed) and transmitted).

PUCCH format 2 transports UCI having a bit size larger than 2 bits andthe modulation symbol is frequency division multiplexed (FDMed) with theDMRS and transmitted. The DMRS is located in symbol indexes #1, #4, #7,and #10 within a resource block given with a density of ⅓. A pseudonoise (PN) sequence is used for a DMRS sequence. The frequency hoppingmay be activated for 2 symbol PUCCH format 2.

PUCCH format 3 does not support multiplexing of UEs in the same physicalresource block, and transports UCI with a bit size larger than 2 bits.In other words the PUCCH resource of PUCCH format 3 includes theorthogonal cover code. The modulation symbol is subjected to timedivision multiplexing (TDM) with the DMRS and transmitted.

PUCCH format 4 supports multiplexing of up to 4 terminals in the samephysical resource block, and transports UCI with a bit size larger than2 bits. In other words the PUCCH resource of PUCCH format 3 includes anorthogonal cover code. The modulation symbol is subjected to timedivision multiplexing (TDM) with the DMRS and transmitted.

Machine Type Communication (MTC)

MTC as a type of data communication including one or more machines andmay be applied to Machine-to-Machine (M2M) or Internet-of-Things (IoT).Here, the machine is an entity that does not require direct humanmanipulation or intervention. For example, the machine includes a smartmeter with a mobile communication module, a vending machine, a portableterminal having an MTC function, etc.

In 3GPP, the MTC may be applied from release 10 and may be implementedto satisfy criteria of low cost and low complexity, enhanced coverage,and low power consumption. For example, a feature for a low-cost MTCdevice is added to 3GPP Release 12 and to this end, UE category 0 isdefined. UE category is an index indicating how many data the UE mayprocess in a communication modem. The UE of UE category 0 uses ahalf-duplex operation having a reduced peak data rate and relieved radiofrequency (RF) requirements, and a single receiving antenna to reducebaseband/RF complexity. In 3GPP Release 12, enhanced MTC (eMTC) isintroduced and the MTC terminal is configured to operate only at 1.08MHz (i.e., 6 RBs) which is a minimum frequency bandwidth supported inlegacy LTE to further reduce a price and power consumption of the MTCUE.

In the following description, the MTC may be mixedly used with termssuch as eMTC, LTE-M1/M2, Bandwidth reduced low complexity/coverageenhanced (BL/CE), non-BL UE (in enhanced coverage), NR MTC, enhancedBUCE, etc., or other equivalent terms. Further, the MT CUE/deviceencompasses a UE/device (e.g., the smart meter, the vending machine, orthe portable terminal with the MTC function) having the MTC function.

FIG. 12 illustrates MTC.

Referring to FIG. 12, the MTC device 100 as a wireless device providingthe MTC may be fixed or mobile. For example, the MTC device 100 includesthe smart meter with the mobile communication module, the vendingmachine, the portable terminal having the MTC function, etc. The BS 200may be connected to the MTC device 100 by using radio access technologyand connected to the MTC server 700 through a wired network. The MTCserver 700 is connected to the MTC devices 100 and provides an MTCservice to the MTC devices 100. The service provided through the MTC hasdiscrimination from a service in communication in which human intervenesin the related art and various categories of services includingtracking, metering, payment, a medical field service, remote control,and the like may be provided. For example, services including electricmeter reading, water level measurement, utilization of a monitoringcamera, reporting of an inventory of the vending machine, and the likemay be provided through the MTC. The MTC has a characteristic in that atransmission data amount is small and uplink/downlink datatransmission/reception occurs occasionally. Accordingly, it is efficientto lower a unit price of the MTC device and reduce battery consumptionaccording to a low data rate. The MTC device generally has low mobility,and as a result, the MTC has a characteristic in that a channelenvironment is hardly changed.

FIG. 13 illustrates physical channels used in MTC and general signaltransmission using the same. In a wireless communication system, the MTCUE receives information from the BS through Downlink (DL) and the UEtransmits information to the BS through Uplink (UL). The informationwhich the BS and the UE transmit and receive includes data and variouscontrol information and there are various physical channels according toa type/use of the information which the BS and the UE transmit andreceive.

A UE that is powered on again while being powered off or enters a newcell performs an initial cell search operation such as synchronizingwith the BS (S1001). To this end, the UE receives a PrimarySynchronization Signal (PSS) and a Secondary Synchronization Signal(SSS) from the BS to synchronize with the BS and obtain information suchas a cell identifier (ID), etc. The PSS/SSS used for the initial cellsearch operation of the UE may be a PSS/SSS of the legacy LTE.Thereafter, the MTC UE may receive a Physical Broadcast Channel (PBCH)from the BS and obtain in-cell broadcast information (S1002). Meanwhile,the UE receives a Downlink Reference Signal (DL RS) in an initial cellsearch step to check a downlink channel state.

Upon completion of the initial cell search, the UE receives MTC PDCCH(MPDCCH) and PDSCH corresponding thereto to obtain more specific systeminformation (S1102).

Thereafter, the UE may perform a random access procedure in order tocomplete an access to the BS (S1003 to S1006). Specifically, the UE maytransmit a preamble through a Physical Random Access Channel (PRACH)(S1003) and receive a Random Access Response (RAR) for the preamblethrough the PDCCH and the PDSCH corresponding thereto (S1004).Thereafter, the UE may transmit a Physical Uplink Shared Channel (PUSCH)by using scheduling information in the RAR (S1005) and perform aContention Resolution Procedure such as the PDCCH and the PDSCHcorresponding thereto (S1006).

The UE that performs the aforementioned procedure may then performreception of an MPDCCH signal and/or a PDSCH signal (S1107) andtransmission of a physical uplink shared channel (PUSCH) signal and/or aphysical uplink control channel (PUCCH) signal (S5080) as a generaluplink/downlink signal transmission procedure. Control informationtransmitted from the UE to the BS is collectively referred to as uplinkcontrol information (UCI). The UCI includes Hybrid Automatic Repeat andreQuest Acknowledgement/Negative-ACK (HARQ ACK/NACK), Scheduling Request(SR), Channel State Information (CSI), etc. The CSI includes a ChannelQuality Indication (CQI), a Precoding Matrix Indicator (PMI), RankIndicator (RI), etc.

FIG. 14 illustrates cell coverage enhancement in MTC.

Various cell coverage extension techniques are being discussed in orderto extend coverage extension or coverage enhancement (CE) of the BS forthe MTC device 100. For example, for the extension of the cell coverage,the BS/UE may transmit one physical channel/signal over multipleoccasions (a bundle of physical channels). Within a bundle section, thephysical channel/signal may be repeatedly transmitted according to apre-defined rule. A receiving apparatus may increase a decoding successrate of the physical channel/signal by decoding a part or the entiretyof the physical channel/signal bundle. Here, the occasion may mean aresource (e.g., time/frequency) in which the physical channel/signal maybe transmitted/received. The occasion for the physical channel/signalmay include a subframe, a slot, or a symbol set in a time domain. Here,the symbol set may be constituted by one or more consecutive OFDM-basedsymbols. The OFDM-based symbols may include an OFDM(A) symbol and aDFT-s-OFDM(A) (=SC-FDM(A)) symbol. The occasion for the physicalchannel/signal may include a frequency band and an RB set in a frequencydomain. For example, PBCH, PRACH, MPDCCH, PDSCH, PUCCH, and PUSCH may berepeatedly transmitted.

FIG. 15 illustrates a signal band for MTC.

Referring to FIG. 15, as a method for lowering the unit price of the MTCUE, the MTC may operate only in a specific band (or channel band)(hereinafter, referred to as an MTC subband or narrowband (NB))regardless of a system bandwidth of a cell. For example, anuplink/downlink operation of the MT CUE may be performed only in afrequency band of 1.08 MHz. 1.08 MHz corresponds to 6 consecutivephysical resource blocks (PRBs) in the LTE system is defined to followthe same cell search and random access procedures as the LTE UE. FIG.15(a) illustrates a case where an MTC subband is configured at a center(e.g., 6 PRBs) of the cell and FIG. 15(b) illustrates a case where aplurality of MTC subbands is configured in the cell. The plurality ofMTC subbands may be consecutively/inconsecutively configured in thefrequency domain. The physical channels/signals for the MTC may betransmitted/received in one MTC subband. In the NR system, the MTCsubband may be defined by considering a frequency range and a subcarrierspacing (SCS). As an example, in the NR system, a size of the MTCsubband may be defined as X consecutive PRBs (i.e., a bandwidth of0.18*X*(2{circumflex over ( )}u) MHz) (see Table A4 for u). Here, X maybe defined as 20 according to the size of a SynchronizationSignal/Physical Broadcast Channel (SS/PBCH). In the NR system, the MTCmay operate in at least one bandwidth part (BWP). In this case, theplurality of MTC subbands may be configured in the BWP.

FIG. 16 illustrates scheduling in legacy LTE and MTC.

Referring to FIG. 16, in the legacy LTE, the PDSCH is scheduled by usingthe PDCCH. Specifically, the PDCCH may be transmitted in first N OFDMsymbols in the subframe (N=1 to 3) and the PDSCH scheduled by the PDCCHis transmitted in the same subframe. Meanwhile, in the MTC, the PDSCH isscheduled by using the MPDCCH. As a result, the MT CUE may monitor anMPDCCH candidate in a search space in the subframe. Here, monitoringincludes blind-decoding the MPDCCH candidates. The MPDCCH transmits theDCI and the DCI includes uplink or downlink scheduling information. TheMPDCCH is FDM-multiplexed with the PDSCH in the subframe. The MPDCCH isrepeatedly transmitted in a maximum of 256 subframes and the DCItransmitted by the MPDCCH includes information on the number of MPDCCHrepetitions. In the case of downlink scheduling, when repeatedtransmission of the MPDCCH ends in subframe #N, the PDSCH scheduled bythe MPDCCH starts to be transmitted in subframe #N+2. The PDSCH may berepeatedly transmitted in a maximum of 2048 subframes. The MPDCCH andthe PDSCH may be transmitted in different MTC subbands. As a result, theMT CUE may perform radio frequency (RF) retuning for receiving the PDSCHafter receiving the MPDCCH. In the case of uplink scheduling, whenrepeated transmission of the MPDCCH ends in subframe #N, the PUSCHscheduled by the MPDCCH starts to be transmitted in subframe #N+4. Whenthe repeated transmission is applied to the physical channel, frequencyhopping is supported between different MTC subbands by the RF retuning.For example, when the PDSCH is repeatedly transmitted in 32 subframes,the PDSCH may be transmitted in a first MTC subband in first 16subframes and the PDSCH may be transmitted in a second MTC subband in 16remaining subframes. The MTC operates in a half duplex mode. HARQretransmission of the MTC is an adaptive asynchronous scheme.

Narrowband Internet of Things (NB-IoT)

NB-IoT represents a narrow-band Internet of Things technology thatsupports a low-power wide area network through a legacy wirelesscommunication system (e.g., LTE, NR). In addition, the NB-IoT may referto a system for supporting low complexity and low power consumptionthrough a narrowband. The NB-IoT system uses OFDM parameters such assubcarrier spacing (SCS) in the same manner as the legacy system, sothat there is no need to separately allocate an additional band for theNB-IoT system. For example, one PRB of the legacy system band may beallocated for the NB-IoT. Since the NB-IoT UE recognizes a single PRB aseach carrier, the PRB and the carrier may be interpreted as the samemeaning in the description of the NB-IoT.

Hereinafter, the description of the NB-IoT mainly focuses on a casewhere the description of the NB-IoT is applied to the legacy LTE system,but the description below may be extensively applied even to a nextgeneration system (e.g., NR system, etc.). Further, in the presentdisclosure, contents related to the NB-IoT may be extensively applied toMTC which aims for similar technical purposes (e.g., low-power,low-cost, coverage enhancement, etc.). Further, the NB-IoT may bereplaced with other equivalent terms such as NB-LTE, NB-IoT enhancement,enhanced NB-IoT, further enhanced NB-IoT, NB-NR, and the like.

FIG. 17 illustrates physical channels used in NB-IoT and general signaltransmission using the same. In the wireless communication system, theUE receives information from the BS through Downlink (DL) and the UEtransmits information from the BS through Uplink (UL). The informationwhich the BS and the UE transmit and receive includes data and variouscontrol information and there are various physical channels according toa type/use of the information which the BS and the UE transmit andreceive.

A UE that is powered on again while being powered off or enters a newcell performs an initial cell search operation such as synchronizingwith the BS (S11). To this end, the UE receives a Narrowband PrimarySynchronization Signal (NPSS) and a Narrowband Secondary SynchronizationSignal (NSSS) from the BS to synchronize with the BS and obtaininformation such as a cell identifier (ID), etc. Thereafter, the UEreceives a Narrowband Physical Broadcast Channel (NPBCH) from the BS toobtain in-cell broadcast information (S12). Meanwhile, the UE receives aDownlink Reference Signal (DL RS) in an initial cell search step tocheck a downlink channel state.

Upon completion of the initial cell search, the UE receives NarrowbandPDCCH (NPDCCH) and Narrowband PDSCH (NPDSCH) corresponding thereto toobtain more specific system information in step S12 (S12).

Thereafter, the UE may perform a random access procedure in order tocomplete an access to the BS (S13 to S16). Specifically, the UE maytransmit a preamble through a Narrowband Physical Random Access Channel(NPRACH) (S13) and receive the Random Access Response (RAR) for thepreamble through the NPDCCH and the NPDSCH corresponding thereto (S14).Thereafter, the UE may transmit a Narrowband Physical Uplink SharedChannel (NPUSCH) by using scheduling information in the RAR (S15) andperform a Contention Resolution Procedure such as the NPDCCH and theNPDSCH corresponding thereto (S16).

The UE that performs the aforementioned procedure may then performreception of the NPDCCH signal and/or NPDSCH signal (S17) and NPUSCHtransmission (S18) as the general uplink/downlink signal transmissionprocedure. Control information transmitted from the UE to the BS iscollectively referred to as uplink control information (UCI). The UCIincludes Hybrid Automatic Repeat and reQuestAcknowledgement/Negative-ACK (HARQ ACK/NACK), Scheduling Request (SR),Channel State Information (CSI), etc. The CSI includes a Channel QualityIndication (CQI), a Precoding Matrix Indicator (PMI), Rank Indicator(RI), etc. In the NB-IoT, the UCI is transmitted through the NPUSCH.According to the request/instruction of the network (e.g., BS), the UEmay transmit the UCI through the NPUSCH periodically, aperiodically, orsemi-persistently.

An NB-IoT frame structure may be configured differently according to thesubcarrier spacing (SCS). FIG. 18 illustrates a frame structure when asubframe spacing is 15 kHz and FIG. 18 illustrates a frame structurewhen a subframe spacing is 3.75 kHz. The frame structure of FIG. 18 maybe used in downlink/uplink and the frame structure of FIG. 19 may beused only in uplink.

Referring to FIG. 18 the NB-IoT frame structure for the subcarrierspacing of 15 kHz may be configured to be the same as the framestructure of the legacy system (i.e., LTE system) (see FIG. 2). That is,a 10-ms NB-IoT frame may include ten 1-ms NB-IoT subframes and a 1-msNB-IoT subframe may include two 0.5-ms NB-IoT slots. Each 0.5-ms NB-IoTslot may include seven symbols. The 15-kHz subcarrier spacing may beapplied to both downlink and uplink. The symbol includes an OFDMA symbolin downlink and an SC-FDMA symbol in uplink. In the frame structure ofFIG. 18, the system band is 1.08 MHz and is defined by 12 subcarriers.The 15-kHz subcarrier spacing is applied to both downlink and uplink andorthogonally with the LTE system is guaranteed, and as a result,coexistence with the LTE system may be facilitated.

Meanwhile, referring to FIG. 19, when the subcarrier spacing is 3.75kHz, the 10-ms NB-IoT frame may include five 2-ms NB-IoT subframes, andthe 2-ms NB-IoT subframe may include seven symbols and one guard period(GP) symbol. The 2-ms NB-IoT subframe may be expressed as an NB-IoT slotor an NB-IoT resource unit (RU). Here, the symbol may include theSC-FDMA symbol. In the frame structure of FIG. 19, the system band is1.08 MHz and is defined by 48 subcarriers. The subcarrier spacing of3.75 kHz may be applied only to the uplink and the orthogonality withthe LTE system may be impaired, resulting in performance degradation dueto interference.

The figure may illustrate an NB-IoT frame structure based on an LTEsystem frame structure and the illustrated NB-IoT frame structure may beextensively applied even to the next-generation system (e.g., NRsystem).

FIG. 20 illustrates three operation modes of NB-IoT. Specifically, FIG.20(a) illustrates an in-band system, FIG. 20(b) illustrates a guard-bandsystem, and FIG. 20(c) illustrates a stand-alone system. Here, thein-band system may be expressed as an in-band mode, the guard-bandsystem may be expressed as guard-band mode, and the stand-alone systemmay be expressed as a stand-alone mode. For convenience, the NB-IoToperation mode is described based on the LTE band, but the LTE band maybe replaced with a band of another system (e.g., NR system band).

The in-band mode means an operation mode to perform the NB-IoT in the(legacy) LTE band. In the in-band mode, some resource blocks of an LTEsystem carrier may be allocated for the NB-IoT. For example, in thein-band mode, specific 1 RB (i.e., PRB) in the LTE band may be allocatedfor the NB-IoT. The in-band mode may be operated in a structure in whichthe NB-IoT coexists in the LTE band. The guard-band mode means anoperation mode to perform the NB-IoT in a reserved space for theguard-band of the (legacy) LTE band. Accordingly, in the guard-bandmode, the guard-band o the LTE carrier not used as the resource block inthe LTE system may be allocated for the NB-IoT. The (legacy) LTE bandmay have a guard-band of at least 100 kHz at the end of each LTE band.The stand-alone mode means an operation mode to perform the NB-IoT in afrequency band independently from the (legacy) LTE band. For example, inthe stand-alone mode, a frequency band (e.g., a GSM carrier to bereallocated in the future) used in a GSM EDGE Radio Access Network(GERAN) may be allocated for the NB-IoT.

The NB-IoT UE searches an anchor carrier in units of 100 kHz and in thein-band and the guard-band, a center frequency of the anchor carriershould be located within ±7.5 kHz from a 100 kHz channel raster.Further, six center PRBs among LTE PRBs are not allocated to the NB-IoT.Accordingly, the anchor carrier may be located only in a specific PRB.

FIG. 21 illustrates a layout of an in-band anchor carrier at an LTEbandwidth of 10 MHz.

Referring to FIG. 21, a direct current (DC) subcarrier is located in thechannel raster. Since a center frequency spacing between adjacent PRBsis 180 kHz, the center frequency is located at ±2.5 kH from the channelraster in the case of PRB indexes 4, 9, 14, 19, 30, 35, 40, and 45.Similarly, the center frequency of the PRB suitable as the anchorcarrier at an LTE bandwidth of 20 MHz is located at ±2.5 kHz from thechannel raster and the center frequency of the PRB suitable as theanchor carrier at LTE bandwidths of 3 MHz, 5 MHz, and 15 MHz is locatedat ±7.5 kHz from the channel raster.

In the case of the guard-band mode, the center frequency is located at±2.5 kHz from the channel raster in the case of a PRB immediatelyadjacent to an edge PRB of LTE at the bandwidths of 10 MHz and 20 MHz.In the case of the bandwidths 3 MHz, 5 MHz, and 15 MHz, a guardfrequency band corresponding to three subcarriers from the edge PRB isused to locate the center frequency of the anchor carrier at ±7.5 kHzfrom the channel raster.

The anchor carrier of the stand-alone mode may be aligned in the 100 kHzchannel raster and all GSM carriers including a DC carrier may be usedas the NB-IoT anchor carrier.

The NB-IoT may support multi-carriers and combinations of in-band andin-band, in-band and guard-band, guard band and guard-band, andstand-alone and stand-alone may be used.

In NB-IoT downlink, physical channels such as a Narrowband PhysicalBroadcast Channel (NPBCH), a Narrowband Physical Downlink Shared Channel(NPDSCH), and a Narrowband Physical Downlink Control Channel (NPDCCH)are provided and physical signals such as a Narrowband PrimarySynchronization Signal (NPSS), a Narrowband Primary SynchronizationSignal (NSSS), and a Narrowband Reference Signal (NRS) are provided.

The NPBCH transfers, to the UE, a Master Information Block-Narrowband(MIB-NB) which is minimum system information which the NB-IoT requiresfor accessing the system. The NPBCH signal may be repeatedly transmittedeight times in total for coverage enhancement. A Transport Block Size(TBS) of the MIB-NB is 34 bits and is newly updated every 64 ms TTIperiod. The MIB-NB includes information such as an operation mode, aSystem Frame Number (SFN), a Hyper-SFN, the number of Cell-specificReference Signal (CRS) ports, a channel raster offset, etc.

FIG. 22 illustrates transmission of an NB-IoT downlink physicalchannel/signal in an FDD LTE system. A downlink physical channel/signalis transmitted through one PRB and supports 15 kHz subcarrierspacing/multi-tone transmission.

Referring to FIG. 22, the NPSS is transmitted in a 6th subframe of everyframe and the NSSS is transmitted in a last (e.g., 10th) subframe ofevery even frame. The UE may obtain frequency, symbol, and framesynchronization using the synchronization signals (NPSS and NSSS) andsearch 504 physical cell IDs (PCIDs) (i.e., BS IDs). The NPBCH istransmitted in a first subframe of every frame and transports theNB-MIB. The NRS is provided as a reference signal for downlink physicalchannel demodulation and is generated in the same scheme as the LTE.However, Physical Cell ID (NB-PCID) (or NCell ID or NB-IoT BS ID) isused as an initialization value for NRS sequence generation. The NRS istransmitted through one or two antenna ports. The NPDCCH and the NPDSCHmay be transmitted in the remaining subframes except for theNPSS/NSSS/NPBCH. The NPDCCH and the NPDSCH may be transmitted togetherin the same subframe. The NPDCCH transports the DCI and the DCI supportsthree types of DCI formats. DCI format NO includes Narrowband PhysicalUplink Shared Channel (NPUSCH) scheduling information and DCI formats N1and N2 include NPDSCH scheduling information. The NPDCCH may berepeatedly transmitted 2048 times in total for coverage enhancement. TheNPDSCH is used for transmitting data (e.g., TB) of transmission channelssuch as a Downlink-Shared Channel (DL-SCH) and a Paging Channel (PCH).The maximum TBS is 680 bits and may be repeatedly transmitted 2048 timesin total for coverage enhancement.

The uplink physical channel includes a Narrowband Physical Random AccessChannel (NPRACH) and the NPUSCH and supports single-tone transmissionand multi-tone transmission. The single-tone transmission is supportedfor the subcarrier spacings of 3.5 kHz and 15 kHz and the multi-tonetransmission is supported only for the subcarrier spacing of 15 kHz.

FIG. 23 illustrates an NPUSCH format.

The NPUSCH supports two formats. NPUSCH format 1 is used for UL-SCHtransmission, and the maximum TBS is 1000 bits. NPUSCH format 2 is usedfor transmission of uplink control information such as HARQ ACKsignaling. NPUSCH format 1 supports the single-/multi-tone transmission,and NPUSCH format 2 supports only the single-tone transmission. In thecase of the single-tone transmission, pi/2-Binary Phase Shift Keying(BPSK) and pi/4-Quadrature Phase Shift Keying (QPSK) are used to reducePeat-to-Average Power Ratio (PAPR). In the NPUSCH, the number of slotsoccupied by one resource unit (RU) may vary according to resourceallocation. The RU represents the smallest resource unit to which the TBis mapped, and is constituted by NULsymb*NULslots consecutive SC-FDMAsymbols in the time domain and NRUsc consecutive subcarriers in thefrequency domain. Here, NULsymb represents the number of SC-FDMA symbolsin the slot, NULslots represents the number of slots, and NRUscrepresents the number of subcarriers constituting the RU.

Table 11 shows the configuration of the RU according to the NPUSCHformat and subcarrier spacing. In the case of TDD, the supported NPUSCHformat and SCS vary according to the uplink-downlink configuration.Table 2 may be referred to for the uplink-downlink configuration.

TABLE 11 Supported NPUSCH Subcarrier uplink-downlink format spacingconfigurations N^(RU) _(sc) N^(UL) _(slots) N^(UL) _(symb) 1 3.75 kHz 1,4 1 16 7 15 kHz 1, 2, 3, 4, 5 1 16 3 8 6 4 12 2 2 3.75 kHz 1, 4 1 4 15kHz 1, 2, 3, 4, 5 1 4

Scheduling information for transmission of UL-SCH data (e.g., UL-SCH TB)is included in DCI format NO, and the DCI format NO is transmittedthrough the NPDCCH. The DCI format NO includes information on the starttime of the NPUSCH, the number of repetitions, the number of RUs usedfor TB transmission, the number of subcarriers, resource locations inthe frequency domain, and MCS.

Referring to FIG. 23, DMRSs are transmitted in one or three SC-FDMAsymbols per slot according to the NPUSCH format. The DMRS is multiplexedwith data (e.g., TB, UCI), and is transmitted only in the RU includingdata transmission.

FIG. 24 illustrates an operation when multi-carriers are configured inFDD NB-IoT.

In FDD NB-IoT, a DL/UL anchor-carrier may be basically configured, and aDL (and UL) non-anchor carrier may be additionally configured.Information on the non-anchor carrier may be included inRRCConnectionReconfiguration. When the DL non-anchor carrier isconfigured (DL add carrier), the UE receives data only in the DLnon-anchor carrier. On the other hand, synchronization signals (NPSS andNSSS), broadcast signals (MIB and SIB), and paging signals are providedonly in the anchor-carrier. When the DL non-anchor carrier isconfigured, the UE listens only to the DL non-anchor carrier while inthe RRC_CONNECTED state. Similarly, when the UL non-anchor carrier isconfigured (UL add carrier), the UE transmits data only in the ULnon-anchor carrier, and simultaneous transmission on the UL non-anchorcarrier and the UL anchor-carrier is not allowed. When the UE istransitioned to the RRC_IDLE state, the UE returns to theanchor-carrier.

FIG. 24 illustrates a case where only the anchor-carrier is configuredfor UE1, the DL/UL non-anchor carrier is additionally configured forUE2, and the DL non-anchor carrier is additionally configured for UE3.As a result, carriers in which data is transmitted/received in each UEare as follows.

-   -   UE1: Data reception (DL anchor-carrier) and data transmission        (UL anchor-carrier)    -   UE2: Data reception (DL non-anchor-carrier) and data        transmission (UL non-anchor-carrier)    -   UE3: Data reception (DL non-anchor-carrier) and data        transmission (UL anchor-carrier)

The NB-IoT UE may not transmit and receive at the same time, and thetransmission/reception operations are limited to one band each.Therefore, even if the multi-carrier is configured, the UE requires onlyone transmission/reception chain of the 180 kHz band.

The present disclosure proposes a method for receiving an emergencychannel (e.g., ETWS or CMAS) in the RRC Connected state when a non-Bandreduced and Low cost (BL) user equipment (UE) operates a coverageextension (CE) mode. The corresponding method may be similarly appliedeven to a case where a specific function is additionally implemented inan MTC dedicated UE (BL UE) other than the non-BL UE.

The emergency channel (or emergency information) is transferred to theUE through a paging channel. However, since the BL/CE UE or the non-BLUE which operates in the CE mode does not receive the paging channel inthe RRC Connected state, a procedure of releasing the RRC connection andchanging the configuration to an RRC Idle or inactive state in order forthe UE to transfer the emergency channel (or emergency channelinformation). For example, the emergency channel may be an Earthquakeand Tsunami Warning System (ETWS), a Commercial Mobile Alert System(CMAS), and/or messages therefor (i.e., ETWS and CMAS).

Accordingly, a time delay required for receiving the emergency channelmay increase and a lot of resources for changing the RRC stateconfiguration may be consumed. In order to solve the problem, a functionis required, in which the UE which operates in the CE mode mayefficiently receive the emergency channel in the RRC Connected state.

However, since the BUCE UE is generally a device such as a sensor, itmay not be relatively important to require the reception of theemergency channel. On the other hand, when a UE (e.g., non-BL UE) whicha general user may carry operates in the CE mode for power consumptionreduction and coverage enhancement, a delay consumed for receiving theemergency channel needs to be minimized.

Accordingly, the present disclosure proposes a method for receiving theemergency channel in the RRC Connected state when the non-BL UE operatesin the CE mode.

Among the emergency channels, the ETWS and/or the CMAS are notinformation to be transmitted separately for each UE, but information tobe similarly received by all UEs located in a specific area. That is, itmay be more efficient in terms of resource use to transmit correspondinginformation to multiple random UEs simultaneously through a channelwhich may be detected rather than individually transfer ETWS and/or CMASnotification to the UEs in the RRC Connected state. In other words, itmay be more efficient in terms of the resource use to simultaneouslytransmit ETWS and/or CMAS notification information to multiple randomUEs through a common channel rather than individually transmitting theETWS and/or CMAS notification information to the UEs.

To this end, the corresponding notification information (or DCI fornotifying the emergency information or direct indication information)needs to be transmitted through the MPDCCH (or PDCCH) of the commonsearch space (CSS) which multiple UE which operate in the CE mode in theRRC Connected state may commonly monitor. The UE that receives thenotification information may obtain emergency channel relatedinformation (or emergency channel information or emergency information)by interpreting information such as a system information block (SIB)(e.g., SIB10, SIB11, and/or SIB12) related to the ETWS and/or CMAS.

The corresponding SIBs (or emergency information) may be scheduledthrough SIB1-BR (or scheduling information for the emergencyinformation) and SIB1-BR scheduling information may be transferredthrough schedulingInfoSIB1-BR of the MIB.

That is, the UE performs a process of receiving a configuration for aUE-specific search space (USS) and a CSS to monitor the emergencychannel notification through RRC, and/or obtaining emergency channel(e.g., ETWS and/or CMAS) notification information from a configuredspecific CSS, and/or obtaining the SIB1-BR scheduling information bydetecting the MIB of the corresponding cell, and/or detecting emergencychannel related SIBs (or emergency information) by detecting the SIB1-BRbased on the SIB1-BR scheduling information, in the RRC Connected state(or mode).

In the present disclosure, blind decoding (BD) means an operation ofperforming, by the UE, decoding for all available PDCCH candidatespre-defined for each subframe (or slot) in order to receive the PDCCH.The BD is one of key factors for determining UE complexity and a batterylife span.

Hereinafter, the present disclosure proposes a method for moreefficiently improving the method for transmitting/receiving theemergency channel.

Specifically, in the present disclosure, a method for monitoring a CSS(or CSS used for notifying the emergency channel) for notifying theemergency channel at a specific period (first embodiment), a method fortransmitting/receiving information indicating whether to changescheduling to be included in the DCI for notifying the emergency channel(second embodiment), and a method for improving blind decoding overheadof the DCI for notifying the emergency channel (third embodiment) aredescribed. For example, the second embodiment may be a method forskipping a process of transmitting/receiving the SIB1-BR schedulinginformation through the MIB and/or scheduling information of SIBsthrough the SIB1-BR after detecting the emergency channel notificationinformation.

Hereinafter, the embodiments described in the present disclosure areonly classified for convenience of description and it is needless to saythat some methods and/or some configurations of any one embodiment maybe substituted with the method and/or configuration of anotherembodiment or may be applied in combination with each other.

In the present disclosure, ‘A/B’ may be interpreted as ‘A and B’, ‘A orB’, and/or ‘A and/or B’.

First Embodiment

First, a method for monitoring the CSS for notifying the emergencychannel at a specific period is described.

Hereinafter, methods to be described are just classified for convenienceand it is needless to say that the configuration of any one method maybe substituted with the configuration of another method or may beapplied in combination with each other.

When the non-BL UE operates in the CE mode, the operation may vary foreach CE mode.

For example, in the case of CE mode A, the UE may attempt tosimultaneously detect Type0 CSS (e.g., Type0-MPDCCH CSS) in aUE-specific Search Space (USS) narrow band (NB) in which MPDCCHcandidates for unicast use may be transmitted in the RRC Connectedstate.

Here, Type0 CSS may be a channel or a search space used for uplinkTransmit Power Control (TPC) of the UE. The DCI included in thecorresponding search space (SS) may be simultaneously detected bymultiple UEs. Each UE may interpret a specific field indicated for eachUE as TPC information to be used thereby and disregard the remainingfields. That is, Type0 CSS may be derived by the USS configured for eachUE and a location of information in the DCI to be referred to for theTPC for each UE may be configured to be UE specific.

In this case, when some fields of the DCI transmitted to Type0 CSS areconfigured to be expected as information used for notifying theemergency channel to multiple users (or UEs) monitoring thecorresponding DCI, the corresponding DCI may be used together with thetransmission of the legacy TPC information. In other words, theemergency channel notification information may be included in the DCItransmitted to Type0 CSS. That is, each UE may use some fields as theemergency channel notification information shared with another userwhile interpreting a specific field as the TPC information in the DCIdetected in Type0 CSS.

On the other hand, a UE which operates in CE mode B may be configured toadditionally monitor the same or similar CSS (e.g., Type0′ CSS) as or toType0 CSS of CE mode A in USS NB in which MPDCCH candidates for unicastuse may be transmitted in the RRC Connected state and may use the CSS asthe channel for notifying the emergency channel.

Unlike CE mode A, in the case of Type0′ CSS of CE mode B, all fields ofthe DCI may be used for transferring information related to thenotification of the emergency channel. In other words, in the case ofType0′ CSS of CE mode B, all fields of the DCI may be used as theemergency channel notification information.

And/or, when the non-BL UE operates in the CE mode, the non-BL UE mayoperate similarly regardless of the CE mode. For example, the non-BL UEmay operate by using one of CE mode A or B detecting method describedabove. For example, the UE which operates in CE mode A and/or the UEwhich operates in CE mode B may interpret a first field of the DCIdetected in Type0 CSS as the TPC information and interpret a secondfield as the emergency channel notification information. For example,the UE which operates in CE mode A and/or the UE which operates in CEmode B may interpret the DCI detected in Type0′ CSS as the emergencychannel notification information.

The Type0 CSS or Type0′ CSS based emergency channel notifying method maybe used for notifying the emergency channel without transitioning theRRC states of the UEs in the RRC Connected state.

However, an interpretation timing of a specific field for correspondingchannel monitoring and emergency channel notification may be need to beminimized in terms of power saving and false alarm. In other words,monitoring the DCI including the emergency channel notification needs tobe minimized in Type0 CSS or Type0′ CSS in terms of power saving andfalse detection. For example, interpretation of emergency channelinformation transmission field (e.g., field of the emergency channelnotification information) of Type0 CSS and/or a detection attempt timing(or DCI detection attempt timing) of Type0′ CSS may be limited to atiming when the UE attempts to detect the paging channel in the RRC Idlemode.

That is, in the case of the UE in CE mode B, the UE may be allowed toattempt to detect Type0′ CSS only at a specific period and/or timinginstead of detecting Type0′ CSS every USS detection attempt. Thespecific period and/or timing may be a value derived from a periodand/or timing at which the corresponding UE or UEs sharing correspondingType0′ CSS monitor the paging channel in the RRC Idle state. Forexample, the period and/or timing may be a paging cycle, a paging frame(PF), a paging occasion (PO), and/or a UE identifier (UE_ID).

For example, in the UE which operates in CE mode B, detection of Type0′CSS may be attempted at a specific and/or timing.

And/or, UEs that interpret the emergency channel notification field(e.g., emergency notification information) in Type0 CSS may be the sameas each other. That is, each time the Type0 CSS is detected, thecorresponding field is not interpreted as the emergency channelnotification information, but every period or only at a timing derivedfrom a period and/or timing at which the corresponding UE or the UEsharing the corresponding Type0′ CSS monitors the paging channel in theRRC Idle state, the corresponding field may be interpreted as validemergency channel notification information. For example, the periodand/or timing of monitoring the paging channel in the RRC Idle state maymean a period and/or timing derived by the paging cycle, the pagingframe, the paging occasion, and/or the UE identifier.

For example, the UE which operates in CE mode A may decode Type0 CSS inthe RRC connected state regardless of the paging cycle. However,interpretation and application of a specific field reserved as the ETWSand/or CMAS in the corresponding DCI may be performed only at a specificperiod and/or timing related to the paging cycle, the paging frame, thepaging occasion, and/or the UE identifier of the corresponding UE.

For example, in the case of the UE which operates in CE mode B, Type0CSS is configured based on USS, but in respect to the timing when eachUE attempts to decode the corresponding DCI, the decoding of thecorresponding DCI may be allowed to be performed only at the pagingcycle of the corresponding UE and/or a specific time (e.g., PO or PF)related thereto. In other words, Type0 CSS is configured based on USS,but each UE may attempt decode the DCI only at the paging cycle of thecorresponding UE and/or the specific time (e.g., PO or PF) relatedthereto.

And/or, Type0′ CSS is derived from the USS configuration of thecorresponding UE, but in respect to the timing when each UE attempts todetect the DCI of the corresponding search space, the DCI detection maybe performed only at a specific period and/or timing related to thepaging cycle, the paging frame, the paging occasion, and/or the UEidentifier of the corresponding UE. In other words, Type0′ CSS isderived from the USS configuration of the corresponding UE, but each UEmay attempt to detect the DCI only at a specific period and/or timingrelated to the paging cycle, the paging frame, the paging occasion,and/or the UE identifier of the corresponding UE.

Second Embodiment

Next, a method for transmitting/receiving the DCI for notifying theemergency channel including information indicating whether to change thescheduling will be described. For example, the BS and/or UE may transmitthe DCI for notifying the emergency channel including SIB-BR schedulingrelated information.

Hereinafter, methods to be described are just classified for convenienceand it is needless to say that the configuration of any one method maybe substituted with the configuration of another method or may beapplied in combination with each other.

As described above, the UE that receives the emergency channelnotification information performs a procedure of obtaining the SIB1-BRscheduling information through the MIB, then obtaining schedulinginformation of the remaining SIBs by detecting SIB1-BR, and receivingemergency channel information related SIBs. In the present disclosure,the emergency channel information related SIBs (e.g., SIB10, SIB11,SIB12, etc.) may be referred to as eSIBs.

In other words, the UE that receives the emergency channel notificationinformation may receive the MIB including the SIB1-BR schedulinginformation, receive the SIB1-BR including the scheduling information ofthe SIBs based on the SIB1-BR scheduling information, and receive SIBs(or emergency channel information) based on scheduling information ofSIB1s.

In this case, when eSIBs start to be transmitted, the remaining SIBscheduling information included in SIB1-BR is changed, but thescheduling information of SIB1-BR itself may be the same as a timingbefore eSIBs are transmitted. In this case, if the BS together transmitsthe emergency channel notification information (e.g., DCI of Type0 CSSor Type0′ CSS of the proposal) including whether the SIB1-BR schedulinginformation is changed through comparison with SIB1-BR schedulinginformation before a specific timing, when the SIB1-BR schedulinginformation is not changed, the UE may skip the detection attempt of theMIB.

For example, the DCI may include information indicating whether theemergency channel notification information and/or the SIB1-BR schedulinginformation is changed. The UE may check whether the SIB-BR schedulinginformation is not changed based on the corresponding DCI and skipreception of the MIB. And/or, the UE may confirm that the SIB-BRscheduling information is changed based on the corresponding DCI andreceive the MIB.

And/or, the SIB1-BR scheduling information may mean schedulinginformation of eSIBs including SIB1-BR. For example, the UE may checkwhether the scheduling information of eSIBs is not changed based on theDCI and skip reception of the SIB1-BR. And/or, the UE may confirm thatthe scheduling information of eSIBs is changed based on thecorresponding DCI and receive the SIB1-BR. And/or, the SIB1-BRscheduling information may mean information including the schedulinginformation of SIB1-BR and the scheduling information of eSIBs.

And/or, in the Type0 CSS or Type0′ CSS of the proposal, the SIB1-BRscheduling information may be directly indicated. For example, the DCImay include the emergency channel information and/or the SIB1-BRscheduling information. The UE may receive the SIB1-BR schedulinginformation based on the corresponding DCI and may receive SIB1-BR basedon the SIB1-BR scheduling information. And/or, the UE may receive theSIB1-BR scheduling information based on the corresponding DCI and mayreceive eSIBs based on the SIB1-BR scheduling information.

And/or, if only the information indicating whether to change the SIB1-BRscheduling information is transferred together with the emergencychannel notification information, defining a previous SIB1-BR schedulinginformation section which becomes a change criterion of the SIB1-BRscheduling information is required. That is, since whether the SIB1-BRscheduling information is changed is a relative definition, when whetherto the SIB1-BR scheduling information is changed is applied based on atiming when each obtains the SIB1-BR scheduling information at apredetermined time, the BS does not know an accurate timing when each UEobtains the SIB1-BR scheduling information and the BS does notaccurately know at which timing the SIB1-BR scheduling information ischanged or maintained based on the SIB1-BR scheduling informationbetween the UEs.

To this end, a timing of the “previous SIB1-BR scheduling information”as the criterion may be configured based on a specific period P of theBS. For example, parameters such as System Information ModificationPeriod, BCCH modification period, or Physical Broadcast Channel (PBCH)Transmission Time Interval (TTI) may be utilized. That is, the BS maymake whether the SIB1-BR scheduling information at the correspondingtiming is updated based on the specific period be included in theemergency channel notification information.

However, the emergency channel information may be transmitted for a longtime so that multiple UEs safely receive the corresponding channel. Inother words, the SIB1-BR scheduling information may be the same for along time during which eSIBs are transmitted. In this case, since thetiming of detection and interpretation of the DCI related to the changeof the SIB1-BR scheduling information may be different for each UE,interpretation of the change or maintenance of the SIB1-BR schedulinginformation is required depending on how the change of the SIB1-BRscheduling information is defined.

That is, when the emergency channel notification information isrepeatedly transmitted for a long time, if specific UE group A obtainsthe corresponding information at a first attempt and the other specificUE group B obtains the corresponding information after time P, theinterpretation of the change of the SIB1-BR scheduling information maydiffer between groups A and B. In other words, from the viewpoint of theBS, at an initial time when the SIB1-BR scheduling information isupdated by transmission of eSIBs, it is indicated that the SIB1-BRscheduling is updated through an emergency channel notification-relatedchannel, but if eSIBs are transmitted even after time P, there is a highprobability that the SIB1-BR scheduling information is maintained to bethe same as that before time P and in this case, since the SIB1-BRscheduling information is not changed compared to the SIB1-BR schedulinginformation before time P, the BS transfers, to the UEs, that theSIB1-BR scheduling information is being maintained through the emergencychannel notification-related channel.

In such a situation, UEs that obtain emergency channel notificationrelated information after timing point P from the timing when theSIB1-BR scheduling information is updated may erroneously interpret thatthe SIB1-BR scheduling information is the same as the SIB1-BR schedulinginformation before transmission of eSIBs.

Accordingly, SIB1-BR scheduling update information included in theemergency channel notification information may be defined in a scheme inwhich the SIB1-BR scheduling information is toggled every time theSIB1-BR scheduling information is updated. In this case, in respect to atoggle criterion, the previous SIB1-BR scheduling information before theinitial timing, which indicates that eSIBs in the emergency channelnotification information are transmitted may be designated as ‘0’ whenthe SIB1-BR scheduling information is changed while eSIBs aretransmitted and otherwise, may be designated as ‘1’. Thereafter, theSIB1-BR scheduling information may be designated by a method in whichthe SIB1-BR scheduling information is toggled every time the SIB1-BRscheduling information is updated. And/or, the meaning of ‘0’ and ‘1’may be interpreted and/or designated in reverse.

Third Embodiment

Next, a method for improving blind decoding overhead of the DCI fornotifying the emergency channel will be described.

Hereinafter, methods to be described are just classified for convenienceand it is needless to say that the configuration of any one method maybe substituted with the configuration of another method or may beapplied in combination with each other.

For notifying the emergency channel, there may be a method for using thesame format (e.g., DCI format 6-1A or DCI format 6-1B) as the DCI usedin the USS as the DCI for transmitting the notification of the emergencychannel through Type® CSS (e.g., Type0-MPDCCH CSS) or Type0′ CSS anddistinguishing the DCI through a Radio Network Temporary Identifier(RNTI).

For example, in the case of CE mode A, DCI format 6-0A or DCI format6-1A may be used. A method for using DCI format 6-0A or DCI format 6-1Ahas an advantage in that DCI for UL/DL scheduling and emergency channelnotification may be received in one DCI format without defining a newDCI format when considering that the CSS is a form of using a part ofthe search space of the USS.

However, a DCI size may vary for each UE by a DCI field of whichexistence is determined by a UE-specific RRC configuration. In otherwords, in the case of a first UE, the DCI size may be x1 by theUE-specific RRC configuration and in the case of a second UE, the DCIsize may be x2 (x2≠x1) by UE-specific RRC configuration. In this case,there may be a problem in that the emergency channel notification maynot be efficiently broadcasted to all UEs.

In order to solve such a problem, in respect to the DCI size for theemergency channel notification, all UEs may have the same DCI size byexcluding a field added by the UE-specific RRC configuration. Forexample, the DCI format for the emergency channel notification has DCIformat 6-1A and/or DCI format 6-1B, but the DCI size may be equal to thesize of DCI format 6-1A and/or DCI format 6-1B excluding the field addedby UE-specific RRC configuration. For example, in the UE which operatesin CE mode B, the format of the DCI is the same as DCI format 6-1B, andthe size of the DCI may be equal to a size acquired by excluding Numberof scheduled TB for SC-MTCH field, Information for SC-MCCH changenotification field, Scheduling TBs for Unicast field, and Resourcereservation field from DCI format 6-1B scheduling the PDSCH. Further,Resource block assignment field may also be configured with a size (ornumber of bits) when ce-pdsch-maxBandwidth-config which is RRCconfiguration information is not configured. In other words, the fieldadded by the UE-specific RRC configuration may mean Number of scheduledTB for SC-MTCH field, Information for SC-MCCH change notification field,Scheduling TBs for Unicast field, Resource reservation field, andResource block assignment field when ce-pdsch-maxBandwidth-config as RRCconfiguration information is configured. In other words, the size of theDCI may be

$14 + \left\lceil {\log_{2}\left\lfloor \frac{N_{RB}^{DL}}{6} \right\rfloor} \right\rceil + 1$

bits.

The emergency channel notification information is transmitted to all UEsthat monitor a corresponding narrowband with Type0 CSS or Type0′ CSS asone DCI is transmitted through the method to enhance downlinktransmission efficiency for a scheduling burden of the BS and a blinddecoding burden of the UE.

The method may include determining the DCI size by assuming a specificvalue (e.g., minimum value) for the corresponding field size when thefield size is changed by the UE-specific RRC configuration.

In the method, “by excluding the field added by the UE-specific RRCconfiguration” may include a meaning of “by excluding a field whichexists only when the corresponding DCI is mapped to the USS (MPDCCH CRCscrambled with C-RNTI)” or a meaning of “by configuring only with afield which exists when the corresponding DCI is transmitted with theCSS”. For example, when the format of the DCI for notifying theemergency information is DCI format 6-1a, the DCI size may be equal to asize when DCI format 6-1A is mapped to the common search space.

In the method, in order to prevent additional BD from being increased,DCI may be used, which has the same size as DCI for transferring TPCinformation transmitted with the CSS or fallback DCI. In this case,separate RNTI different from RNTI used for transmitting the DCI fortransferring TPC information transmitted with the CSS or fallback DCImay be used in order to distinguish the DCI. For example, the separateRNTI may be dedicated RNTI for the emergency channel notification.Alternatively, since the DCI for the emergency channel notification isbroadcast information, the separate RNTI may be SI-RNTI. For example,the DCI for notifying the emergency information may be CRC-scrambledwith System Information (SI)-RNTI.

In the case of applying the method, the UE may perform BD for 1) DCIsize k1 for transmitting the emergency channel notification informationand 2) DCI size k2 including the field added by the UE-specific RRCconfiguration and transmitted with the USS, and transmitting UL/DLscheduling information. That is, the UE may perform BD for two DCIsizes. In this case, the same RNTI may be used and the DCI for theemergency channel notification and DCI for UL/DL scheduling may bedistinguished by the DCI size (when k1≠k2 is guaranteed).

And/or, in preparation for the case where k1=k2 exists, k1 and k2 may bedistinguished by using separate RNTI. For example, the case of k1=k2 maybe a case where there is no added field in the case of the UE-specificRRC configuration in the DCI. For example, the separate RNTI may bededicated RNTI for the emergency channel notification or the SI-RNTI.

In this case, the dedicated RNTI for the emergency channel notificationmay be signaled to the UE through the RRC. The BS CRC-scrambles theemergency channel notification DCI with the separate RNTI and theCRC-scrambled DCI with Type0 CSS or Type0′ CSS and the UE maydistinguish the emergency channel notification DCI by performing BD byassuming DCI sizes k1 and k2 in the case of two RNTIs and/or k1≠k2.

And/or, when the emergency channel notification RNTI is separately used,a period of monitoring the DCI for the emergency channel may beconfigured to be different from a period of monitoring the DCI used inthe USS. For example, when the emergency channel notification RNTI isseparately used, attempting to detect Type0′ CSS may be allowed only ata specific period and/or timing. The specific period and/or timing maybe a value derived from a period and/or timing at which thecorresponding UE or UEs sharing corresponding Type0′ CSS monitor thepaging channel in the RRC Idle state. In other words, the specificperiod and/or timing may be a value derived from the paging cycle, thepaging frame, the paging occasion, and/or the UE identifier.

And/or, the method may be applied only to CE mode A.

For example, in the case of CE mode A, the above proposed method fordetermining the DCI size by excluding the field added by the UE-specificRRC configuration may be applied and in the case of CE mode B, the sameDCI size as the DCI format using in USS (e.g., DCI format 6-0B/1 B) maybe configured to be used.

As such, the reason for separately applying the DCI size to CE mode Aand CE mode B is that in the case of CE mode A in the related art, sinceDCI of DCI format 6-0A/1A already transmitted with the USS and DCI(i.e., two sizes) transmitted with Type0 CSS are blind-decoded, when theDCI size for the emergency channel notification is equal to the DCI sizetransmitted with Type0 CSS, additional BD complexity does not increase,while in the case of CE mode B in the related art, since Type0 CSS isnot supported, when the DCI size for the emergency channel notificationis different from DCI format 6-06/1 B, the BD complexity may increase.

When the method is applied by considering this point, the emergencychannel notification is supported without increasing UE complexity andin the case of CE mode A, the emergency channel notification isefficiently broadcasted to all UEs, thereby improving the BS schedulingburden and enhancing downlink transmission efficiency.

According to the method (e.g., the first to third embodiments) of thepresent disclosure, since RRC state transition procedure may be skippedin order for the BL/CE UE which operates in the CE mode to receive theemergency channel information in the RRC Connected state, signalingoverhead of the BS may be minimized and an emergency channel receptiondelay time of the UE may also be minimized. Further, the UEs in the RRCConnected state is allowed to attempt to detect a specific physicallayer channel (e.g., MPDCCH) for receiving the emergency channelinformation only at a specific limited time, thereby minimizingunnecessary power consumption.

It is obvious that since the examples of the embodiments proposed in thepresent disclosure may also be included as one of implementing methodsof the present disclosure, the examples may be regarded as a kind ofembodiments.

Further, as mentioned above, the embodiments proposed in the presentdisclosure may be independently implemented, but may be implemented as acombination (or merge) form of some embodiments. A rule may be definedand/or configured so as for the BS to notify, to the UE, information (orinformation on the rules of the embodiments) on whether to apply theembodiments through pre-defined signaling (e.g., physical layersignaling and/or higher layer signaling).

FIG. 25 is a flowchart for describing an operation method of a userequipment (UE) proposed in the present disclosure.

Referring to FIG. 25, first, a UE (1000/2000 in FIGS. 27 to 31) mayreceive, from a BS, a system information block (SIB) (e.g., SIB1 and/orSIB1-BR) including scheduling information (e.g., schedulingInfoList) foremergency information (e.g., SIB10, SIB11, and/or SIB12) (S2501). Forexample, the emergency information may be an ETWS message or a CMASmessage.

For example, an operation of the UE in step S2501, which receives theSIB may be implemented by apparatuses of FIGS. 27 to 31 to be describedbelow. For example, referring to FIG. 28, one or more processors 1020may control one or more memories 1040 and/or one or more RF units 1060so as to receive the SIB and one or more RF units 1060 may receive theSIB.

And/or, the UE (1000/2000 in FIGS. 27 to 31) may receive, from the BS,configuration information for a search space (S2502).

For example, the operation of the UE in step S2502, which receives theconfiguration information for the search space may be implemented by theapparatuses of FIGS. 27 to 31 to be described below. For example,referring to FIG. 28, one or more processors 1020 may control one ormore memories 1040 and/or one or more RF units 1060 so as to receive theconfiguration information for the search space and one or more RF units1060 may receive the configuration information for the search space.

And/or, the UE (1000/2000 of FIGS. 27 to 31) may receive, from the BS,downlink control information (DCI) for notification of the emergencyinformation in the search space (S2503).

For example, the operation of the UE in step S2503, which receives theDCI may be implemented by the apparatuses of FIGS. 27 to 31 to bedescribed below. For example, referring to FIG. 28, one or moreprocessors 1020 may control one or more memories 1040 and/or one or moreRF units 1060 so as to receive the DCI and one or more RF units 1060 mayreceive the DCI.

And/or, the UE (1000/2000 in FIGS. 27 to 31) may receive, from the BS,the emergency information based on the DCI and the schedulinginformation (S2504).

For example, the operation of the UE in step S2504, which receives theemergency information may be implemented by the apparatuses of FIGS. 27to 31 to be described below. For example, referring to FIG. 28, one ormore processors 1020 may control one or more memories 1040 and/or one ormore RF units 1060 so as to receive the emergency information and one ormore RF units 1060 may receive the emergency information.

In particular, the format of the DCI is the same as a DCI format forscheduling a Physical Downlink Shared Channel (PDSCH) (e.g., MPDCCH)related to MTC, and the DCI may have a size acquired by excludinginformation added by Radio Resource Control (RRC) configurationinformation from the DCI format.

For example, the DCI format may be DCI format 6-1A or DCI format 6-1B.

For example, the size of the DCI may be the same as the DCI of DCIformat 6-1A or DCI format 6-1B mapped to the common search space. Forexample, based on the format of the DCI being the DCI format 6-1A, thesize of the DCI may be the same as the DCI of DCI format 6-1A mapped tothe common search space.

For example, in the UE which operates in CE mode B, the format of theDCI is the same as DCI format 6-1B, and the size of the DCI may be equalto a size acquired by excluding Number of scheduled TB for SC-MTCHfield, Information for SC-MCCH change notification field, Scheduling TBsfor Unicast field, and Resource reservation field from DCI format 6-1Bscheduling the PDSCH. Further, Resource block assignment field may alsobe configured with a size (or number of bits) whence-pdsch-maxBandwidth-config which is RRC configuration information isnot configured.

And/or, based on the DCI being the DCI format 6-1A, the UE may be a UEwhich operates in CE mode A and based on the DCI being the DCI format6-1B, the UE may be a UE which operates in CE mode B. For example, whenthe DCI is DCI format 6-1A, the UE may be a UE which operates in CE modeA. For example, when the DCI is DCI format 6-1B, the UE may be a UEwhich operates in CE mode B.

For example, the search space is a type 0-MTC Physical Downlink ControlChannel (MPDCCH) (e.g., MPDCCH) common search space.

And/or, the DCI for notification of the emergency information isCRC-scrambled by a System Information (SI)-Radio Network TemporaryIdentifier (RNTI).

And/or, the DCI for notification of the emergency information may bereceived through an MTC Physical Downlink Control Channel (PDCCH).

And/or, the UE may operate in an RRC connection state.

And/or, the UE (1000/2000 of FIGS. 27 to 31) may receive, from the BS, amaster information block (MIB) including the scheduling information(e.g., schedulingInfoSIB1-BR) for the SIB.

For example, the operation of the UE receiving the MIB may beimplemented by the apparatuses of FIGS. 27 to 31 to be described below.For example, referring to FIG. 28, one or more processors 1020 maycontrol one or more memories 1040 and/or one or more RF units 1060 so asto receive the MIB and one or more RF units 1060 may receive the MIB.

The operation of the UE described by referring to FIG. 25 is the same asthe operations (e.g., the first to third embodiments) of the UEdescribed by referring to FIGS. 1 to 24, so a detailed descriptionthereof will be omitted.

The signaling and operation may be implemented by the apparatuses (e.g.,FIGS. 27 to 31) to be described below. For example, the signaling andoperation may be processed by one or more processors 1010 and 2020 ofFIGS. 27 to 31 and the signaling and operation may be stored in memories(e.g., 1040 and 2040) in the form of an instruction/program (e.g.,instruction or executable code) for driving at least one processor(e.g., 1010 and 2020) of FIGS. 27 to 31.

For example, in an apparatus including one or more memories and one ormore processors functionally connected to the one or more memories, theone or more processors are configured for the apparatus to receive, froma BS, a system information block (SIB) including scheduling informationfor emergency information, receive, from the BS, configurationinformation for a search space, receive, from the BS, Downlink ControlInformation (DCI) for notification of the emergency information in thesearch space, and receive, from the BS, the emergency information basedon the DCI and the scheduling information, but a format of the DCI maybe the same as a DCI format for scheduling a Physical Downlink SharedChannel (PDSCH) related to the MTC, and the DCI may have a sizeexcluding information added by Radio Resource Control (RRC)configuration information in the DCI format.

As another example, in non-transitory computer readable medium (CRM)storing one or more instructions, one or more instructions executable byone or more processors control a UE to receive, from a BS, a SystemInformation Block (SIB) including scheduling information for emergencyinformation, receive, from the BS, configuration information for asearch space, receive, from the BS, Downlink Control Information (DCI)for notification of the emergency information in the search space, andreceive, from the BS, the emergency information based on the DCI and thescheduling information, but a format of the DCI may be the same as a DCIformat for scheduling a Physical Downlink Shared Channel (PDSCH) relatedto the MTC, and the DCI may have a size excluding information added byRadio Resource Control (RRC) configuration information in the DCIformat.

FIG. 26 is a flowchart for describing an operation method of a basestation (BS) proposed in the present disclosure.

Referring to FIG. 26, first, a BS (1000/2000 in FIGS. 27 to 31) maytransmit, from a UE, a system information block (SIB) (e.g., SIB1 and/orSIB1-BR) including scheduling information (e.g., schedulingInfoList) foremergency information (e.g., SIB10, SIB11, and/or SIB12) (S2601). Forexample, the emergency information may be an ETWS message or a CMASmessage.

For example, an operation of the BS in step S2601, which transmits theSIB may be implemented by apparatuses of FIGS. 27 to 31 to be describedbelow. For example, referring to FIG. 28, one or more processors 1020may control one or more memories 1040 and/or one or more RF units 1060so as to transmit the SIB and one or more RF units 1060 may transmit theSIB.

And/or, the BS (1000/2000 in FIGS. 27 to 31) may transmit, to the UE,configuration information for a search space (S2602).

For example, the operation of the BS in step S6502, which transmits theconfiguration information for the search space may be implemented by theapparatuses of FIGS. 27 to 31 to be described below. For example,referring to FIG. 28, one or more processors 1020 may control one ormore memories 1040 and/or one or more RF units 1060 so as to transmitthe configuration information for the search space and one or more RFunits 1060 may transmit the configuration information for the searchspace.

And/or, the BS (1000/2000 of FIGS. 27 to 31) may transmit, to the UE,downlink control information (DCI) for notification of the emergencyinformation in the search space (S2603).

For example, the operation of the BS in step S2603, which transmits theDCI may be implemented by apparatuses of FIGS. 27 to 31 to be describedbelow. For example, referring to FIG. 28, one or more processors 1020may control one or more memories 1040 and/or one or more RF units 1060so as to transmit the DCI and one or more RF units 1060 may transmit theDCI.

And/or, the BS (1000/2000 in FIGS. 27 to 31) may transmit, to the UE,the emergency information based on the DCI and the schedulinginformation (S2604).

For example, the operation of the BS in step S2604, which transmits theemergency information may be implemented by apparatuses of FIGS. 27 to31 to be described below. For example, referring to FIG. 28, one or moreprocessors 1020 may control one or more memories 1040 and/or one or moreRF units 1060 so as to transmit the emergency information and one ormore RF units 1060 may transmit the emergency information.

In particular, the format of the DCI is the same as a DCI format forscheduling a Physical Downlink Shared Channel (PDSCH) (e.g., MPDCCH)related to MTC, and the DCI may have a size acquired by excludinginformation added by Radio Resource Control (RRC) configurationinformation from the DCI format.

For example, the DCI format may be DCI format 6-1A or DCI format 6-1B.

For example, the size of the DCI may be the same as the DCI of DCIformat 6-1A or DCI format 6-1B mapped to the common search space. Forexample, based on the format of the DCI being the DCI format 6-1A, thesize of the DCI may be the same as the DCI of DCI format 6-1A mapped tothe common search space.

For example, in the UE which operates in CE mode B, the format of theDCI is the same as DCI format 6-1B, and the size of the DCI may be equalto a size acquired by excluding Number of scheduled TB for SC-MTCHfield, Information for SC-MCCH change notification field, Scheduling TBsfor Unicast field, and Resource reservation field from DCI format 6-1Bscheduling the PDSCH. Further, Resource block assignment field may alsobe configured with a size (or number of bits) whence-pdsch-maxBandwidth-config which is RRC configuration information isnot configured.

And/or, based on the DCI being the DCI format 6-1A, the UE may be a UEwhich operates in CE mode A and based on the DCI being the DCI format6-1B, the UE may be a UE which operates in CE mode B. For example, whenthe DCI is DCI format 6-1A, the UE may be a UE which operates in CE modeA. For example, when the DCI is DCI format 6-1B, the UE may be a UEwhich operates in CE mode B.

For example, the search space is a type 0-MTC Physical Downlink ControlChannel (MPDCCH) (e.g., MPDCCH) common search space.

And/or, the DCI for notification of the emergency information isCRC-scrambled by a System Information (SI)-Radio Network TemporaryIdentifier (RNTI).

And/or, the DCI for notification of the emergency information may bereceived through an MTC Physical Downlink Control Channel (PDCCH).

And/or, the UE may operate in an RRC connection state.

And/or, the BS (1000/2000 of FIGS. 27 to 31) may transmit, to the UE, amaster information block (MIB) including the scheduling information(e.g., schedulingInfoSIB1-BR) for the SIB.

For example, the operation of the BS transmitting the MIB may beimplemented by the apparatuses of FIGS. 27 to 31 to be described below.For example, referring to FIG. 28, one or more processors 1020 maycontrol one or more memories 1040 and/or one or more RF units 1060 so asto transmit the MIB and one or more RF units 1060 may transmit the MIB.

The operation of the BS described by referring to FIG. 26 is the same asthe operations (e.g., the first to third embodiments) of the BSdescribed by referring to FIGS. 1 to 24, so a detailed descriptionthereof will be omitted.

The signaling and operation may be implemented by the apparatuses (e.g.,FIGS. 27 to 31) to be described below. For example, the signaling andoperation may be processed by one or more processors 1010 and 2020 ofFIGS. 27 to 31 and the signaling and operation may be stored in memories(e.g., 1040 and 2040) in the form of an instruction/program (e.g.,instruction or executable code) for driving at least one processor(e.g., 1010 and 2020) of FIGS. 27 to 31.

For example, in an apparatus including one or more memories and one ormore processors functionally connected to the one or more memories, theone or more processors are configured for the apparatus to transmit, toa UE, a system information block (SIB) including scheduling informationfor emergency information, transmit, to the UE, configurationinformation for a search space, transmit, to the UE, Downlink ControlInformation (DCI) for notification of the emergency information in thesearch space, and transmit, to the UE, the emergency information basedon the DCI and the scheduling information, but a format of the DCI maybe the same as a DCI format for scheduling a Physical Downlink SharedChannel (PDSCH) related to the MTC, and the DCI may have a sizeexcluding information added by Radio Resource Control (RRC)configuration information in the DCI format.

As another example, in non-transitory computer readable medium (CRM)storing one or more instructions, one or more instructions executable byone or more processors control a BS to transmit, to a UE, a SystemInformation Block (SIB) including scheduling information for emergencyinformation, transmit, to the UE, configuration information for a searchspace, transmit, to the UE, Downlink Control Information (DCI) fornotification of the emergency information in the search space, andtransmit, to the UE, the emergency information based on the DCI and thescheduling information, but a format of the DCI may be the same as a DCIformat for scheduling a Physical Downlink Shared Channel (PDSCH) relatedto the MTC, and the DCI may have a size excluding information added byRadio Resource Control (RRC) configuration information in the DCIformat.

Example of Communication System to which Present Disclosure is Applied

Although not limited thereto, but various descriptions, functions,procedures, proposals, methods, and/or operation flowcharts of thepresent disclosure, which are disclosed in this document may be appliedto various fields requiring wireless communications/connections (e.g.,5G) between devices.

Hereinafter, the communication system will be described in more detailwith reference to drawings. In the following drawings/descriptions, thesame reference numerals will refer to the same or corresponding hardwareblocks, software blocks, or functional blocks if not differentlydescribed.

FIG. 27 illustrates a communication system 10 applied to the presentdisclosure.

Referring to 27, a communication system 10 applied to the presentdisclosure includes a wireless device, a BS, and a network. Here, thewireless device may mean a device that performs communication by using awireless access technology (e.g., 5G New RAT (NR) or Long Term Evolution(LTE)) and may be referred to as a communication/wireless/5G device.Although not limited thereto, the wireless device may include a robot1000 a, vehicles 1000 b-1 and 1000 b-2, an eXtended Reality (XR) device1000 c, a hand-held device 1000 d, a home appliance 1000 e, an Internetof Thing (IoT) device 1000 f, and an AI device/server 4000. For example,the vehicle may include a vehicle with a wireless communicationfunction, an autonomous driving vehicle, a vehicle capable of performinginter-vehicle communication, and the like. Here, the vehicle may includean Unmanned Aerial Vehicle (UAV) (e.g., drone). The XR device mayinclude an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality(MR) device and may be implemented as a form such as a head-mounteddevice (HMD), a head-up display (HUD) provided in the vehicle, atelevision, a smart phone, a computer, a wearable device, a homeappliance device, digital signage, a vehicle, a robot, etc. Thehand-held device may include the smart phone, a smart pad, a wearabledevice (e.g., a smart watch, a smart glass), a computer (e.g., anotebook, etc.), and the like. The home appliance device may include aTV, a refrigerator, a washing machine, and the like. The IoT device mayinclude a sensor, a smart meter, and the like. For example, the BS andthe network may be implemented even the wireless device and a specificwireless device 2,000 a may operate a BS/network node for anotherwireless device.

The wireless devices 1000 a to 1000 f may be connected to a network 3000through a BS 2000. An artificial intelligence (AI) technology may beapplied to the wireless devices 1000 a to 100 f and the wireless devices1000 a to 1000 f may be connected to an AI server 4000 through thenetwork 3000. The network 3000 may be configured by using a 3G network,a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wirelessdevices 1000 a to 1000 f may communicate with each other through the BS2000/network 3000, but may directly communicate with each other withoutgoing through the BS/network (sidelink communication). For example, thevehicles 1000 b-1 and 1000 b-2 may perform direct communication (e.g.,Vehicle to Vehicle (V2V)/Vehicle to everything (V2X) communication).Further, the IoT device (e.g., sensor) may perform direct communicationwith other IoT devices (e.g., sensor) or other wireless devices 1000 ato 1000 f.

Wireless communications/connections 1500 a, 1500 b, and 1500 c may bemade between the wireless devices 1000 a to 1000 f and the BS 2000 andbetween the BS 2000 and the BS 2000. Here, the wirelesscommunication/connection may be made through various wireless accesstechnologies (e.g., 5G NR) such as uplink/downlink communication 1500 a,sidelink communication 1500 b (or D2D communication), and inter-BScommunication 1500 c (e.g., relay, Integrated Access Backhaul (IAB)).The wireless device and the BS/the wireless device and the BS and the BSmay transmit/receive radio signals to/from each other through wirelesscommunications/connections 1500 a, 1500 b, and 1500 c. For example, thewireless communications/connections 1500 a, 1500 b, and 1500 c maytransmit/receive signals through various physical channels. To this end,based on various proposals of the present disclosure, at least some ofvarious configuration information setting processes, various signalprocessing processes (e.g., channel encoding/decoding,modulation/demodulation, resource mapping/demapping, etc.), a resourceallocation process, and the like for transmission/reception of the radiosignal may be performed.

Example of Wireless Device to which Present Disclosure is Applied

FIG. 28 illustrates a wireless device which may be applied to thepresent disclosure.

Referring to FIG. 28, a first wireless device 1000 and a second wirelessdevice 2000 may transmit/receive radio signals through various wirelessaccess technologies (e.g., LTE and NR). Here, the first wireless device1000 and the second wireless device 2000 may correspond to a wirelessdevice 1000 x and a BS 2000 and/or a wireless device 1000 x and awireless device 1000 x of FIG. 32.

The first wireless device 1000 may include one or more processors 1020and one or more memories 1040 and additionally further include one ormore transceivers 1060 and/or one or more antennas 1080. The processor1020 may control the memory 1040 and/or the transceiver 1060 and may beconfigured to implement descriptions, functions, procedures, proposals,methods, and/or operation flows disclosed in the present disclosure. Forexample, the processor 1020 may process information in the memory 1040and generate a first information/signal and then transmit a radio signalincluding the first information/signal through the transceiver 1060.Further, the processor 1020 may receive a radio signal including asecond information/signal through the transceiver 1060 and then store inthe memory 1040 information obtained from signal processing of thesecond information/signal. The memory 1040 may connected to theprocessor 1020 and store various information related to an operation ofthe processor 1020. For example, the memory 1040 may store a softwarecode including instructions for performing some or all of processescontrolled by the processor 1020 or performing the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in the present disclosure. Here, the processor 1020 and thememory 1040 may be a part of a communication modem/circuit/chipdesignated to implement the wireless communication technology (e.g., LTEand NR). The transceiver 1060 may be connected to the processor 1020 andmay transmit and/or receive the radio signals through one or moreantennas 1080. The transceiver 1060 may include a transmitter and/or areceiver. The transceiver 1060 may be mixed with a radio frequency (RF)unit. In the present disclosure, the wireless device may mean thecommunication modem/circuit/chip.

The second wireless device 2000 may include one or more processors 2020and one or more memories 2040 and additionally further include one ormore transceivers 2060 and/or one or more antennas 2080. The processor2020 may control the memory 2040 and/or the transceiver 2060 and may beconfigured to implement descriptions, functions, procedures, proposals,methods, and/or operation flows disclosed in the present disclosure. Forexample, the processor 2020 may process information in the memory 2040and generate a third information/signal and then transmit a radio signalincluding the third information/signal through the transceiver 2060.Further, the processor 2020 may receive a radio signal including afourth information/signal through the transceiver 2060 and then store inthe memory 2040 information obtained from signal processing of thefourth information/signal. The memory 2040 may connected to theprocessor 2020 and store various information related to an operation ofthe processor 2020. For example, the memory 2040 may store a softwarecode including instructions for performing some or all of processescontrolled by the processor 2020 or performing the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in the present disclosure. Here, the processor 2020 and thememory 2040 may be a part of a communication modem/circuit/chipdesignated to implement the wireless communication technology (e.g., LTEand NR). The transceiver 2060 may be connected to the processor 2020 andmay transmit and/or receive the radio signals through one or moreantennas 2080. The transceiver 2060 may include a transmitter and/or areceiver and the transceiver 2060 may be mixed with the RF unit. In thepresent disclosure, the wireless device may mean the communicationmodem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 1000 and 2000will be described in more detail. Although not limited thereto, one ormore protocol layers may be implemented by one or more processors 1020and 2020. For example, one or more processors 1020 and 2020 mayimplement one or more layers (e.g., functional layers such as PHY, MAC,RLC, PDCP, RRC, and SDAP). One or more processors 1020 and 2020 maygenerate one or more protocol data units (PDUs) and/or one or moreservice data units (SDUs) according to the descriptions, functions,procedures, proposals, methods, and/or operation flowcharts disclosed inthe present disclosure. One or more processors 1020 and 2020 maygenerate a message, control information, data, or information accordingto the descriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in the present disclosure. One or moreprocessors 1020 and 2020 may generate a signal (e.g., a baseband signal)including the PDU, the SDU, the message, the control information, thedata, or the information according to the function, the procedure, theproposal, and/or the method disclosed in the present disclosure andprovide the generated signal to one or more transceivers 1060 and 2060.One or more processors 1020 and 2020 may receive the signal (e.g.baseband signal) from one or more transceivers 1060 and 2060 and acquirethe PDU, the SDU, the message, the control information, the data, or theinformation according to the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in the presentdisclosure.

One or more processors 1020 and 2020 may be referred to as a controller,a microcontroller, a microprocessor, or a microcomputer. One or moreprocessors 1020 and 2020 may be implemented by hardware, firmware,software, or a combination thereof. As one example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in one or moreprocessors 1020 and 2020. The descriptions, functions, procedures,proposals, and/or operation flowcharts disclosed in the presentdisclosure may be implemented by using firmware or software and thefirmware or software may be implemented to include modules, procedures,functions, and the like. Firmware or software configured to perform thedescriptions, functions, procedures, proposals, and/or operationflowcharts disclosed in the present disclosure may be included in one ormore processors 1020 and 2020 or stored in one or more memories 1040 and2040 and driven by one or more processors 1020 and 2020. Thedescriptions, functions, procedures, proposals, and/or operationflowcharts disclosed in the present disclosure may be implemented byusing firmware or software in the form of a code, the instruction and/ora set form of the instruction.

One or more memories 1040 and 2040 may be connected to one or moreprocessors 1020 and 2020 and may store various types of data, signals,messages, information, programs, codes, instructions, and/orinstructions. One or more memories 1040 and 2040 may be configured by aROM, a RAM, an EPROM, a flash memory, a hard drive, a register, a cachememory, a computer reading storage medium, and/or a combination thereof.One or more memories 1040 and 2040 may be positioned inside and/oroutside one or more processors 1020 and 2020. Further, one or morememories 1040 and 2040 may be connected to one or more processors 1020and 2020 through various technologies such as wired or wirelessconnection.

One or more transceivers 1060 and 2060 may transmit to one or more otherdevices user data, control information, a wireless signal/channel, etc.,mentioned in the methods and/or operation flowcharts of the presentdisclosure. One or more transceivers 1060 and 2060 may receive from oneor more other devices user data, control information, a wirelesssignal/channel, etc., mentioned in the descriptions, functions,procedures, proposals, methods, and/or operation flowcharts disclosed inthe present disclosure. For example, one or more transceivers 1060 and2060 may be connected to one or more processors 1020 and 2020 andtransmit and receive the radio signals. For example, one or moreprocessors 1020 and 2020 may control one or more transceivers 1060 and2060 to transmit the user data, the control information, or the radiosignal to one or more other devices. Further, one or more processors1020 and 2020 may control one or more transceivers 1060 and 2060 toreceive the user data, the control information, or the radio signal fromone or more other devices. Further, one or more transceivers 1060 and2060 may be connected to one or more antennas 1080 and 2080 and one ormore transceivers 1060 and 2060 may be configured to transmit andreceive the user data, control information, wireless signal/channel,etc., mentioned in the descriptions, functions, procedures, proposals,methods, and/or operation flowcharts disclosed in the present disclosurethrough one or more antennas 1080 and 2080. In the present disclosureone or more antennas may be a plurality of physical antennas or aplurality of logical antennas (e.g., antenna ports). One or moretransceivers 1060 and 2060 may convert the received radio signal/channelfrom an RF band signal to a baseband signal in order to process thereceived user data, control information, radio signal/channel, etc., byusing one or more processors 1020 and 2020. One or more transceivers1060 and 2060 may convert the user data, control information, radiosignal/channel, etc., processed by using one or more processors 1020 and2020, from the baseband signal into the RF band signal. To this end, oneor more transceivers 1060 and 2060 may include an (analog) oscillatorand/or filter.

Example of Signal Processing Circuit to which Present Disclosure isApplied

FIG. 29 illustrates a signal processing circuit for a transmit signal.

Referring to FIG. 29 a signal processing circuit 10000 may include ascrambler 10100, a modulator 10200, a layer mapper 10300, a precoder10400, a resource mapper 10500, and a signal generator 10600. Althoughnot limited thereto, an operation/function of FIG. 29 may be performedby the processors 1020 and 2020 and/or the transceivers 1060 and 2060 ofFIG. 28. Hardware elements of FIG. 29 may be implemented in theprocessors 1020 and 2020 and/or the transceivers 1060 and 2060 of FIG.28. For example, blocks 10100 to 10600 may be implemented in theprocessors 1020 and 2020 of FIG. 28. Further, blocks 10100 to 10500 maybe implemented in the processors 1020 and 2020 of FIG. 28 and the block10600 of FIG. 28 and the block 2760 may be implemented in thetransceivers 1060 and 2060 of FIG. 26.

A codeword may be transformed into a radio signal via the signalprocessing circuit 10000 of FIG. 29. Here, the codeword is an encodedbit sequence of an information block. The information block may includetransport blocks (e.g., a UL-SCH transport block and a DL-SCH transportblock). The radio signal may be transmitted through various physicalchannels (e.g., PUSCH and PDSCH).

Specifically, the codeword may be transformed into a bit sequencescrambled by the scrambler 10100. A scramble sequence used forscrambling may be generated based on an initialization value and theinitialization value may include ID information of a wireless device.The scrambled bit sequence may be modulated into a modulated symbolsequence by the modulator 10200. A modulation scheme may includepi/2-BPSK(pi/2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying),m-QAM (m-Quadrature Amplitude Modulation), etc. A complex modulatedsymbol sequence may be mapped to one or more transport layers by thelayer mapper 10300. Modulated symbols of each transport layer may bemapped to a corresponding antenna port(s) by the precoder 10400(precoding). Output z of the precoder 10400 may be obtained bymultiplying output y of the layer mapper 10300 by precoding matrix W ofN*M. Here, N represents the number of antenna ports and M represents thenumber of transport layers. Here, the precoder 10400 may performprecoding after performing transform precoding (e.g., DFT transform) forcomplex modulated symbols. Further, the precoder 10400 may perform theprecoding without performing the transform precoding.

The resource mapper 10500 may map the modulated symbols of each antennaport to a time-frequency resource. The time-frequency resource mayinclude a plurality of symbols (e.g., CP-OFDMA symbol and DFT-s-OFDMAsymbol) in a time domain and include a plurality of subcarriers in afrequency domain. The signal generator 10600 may generate the radiosignal from the mapped modulated symbols and the generated radio signalmay be transmitted to another device through each antenna. To this end,the signal generator 10600 may include an Inverse Fast Fourier Transform(IFFT) module, a Cyclic Prefix (CP) insertor, a Digital-to-AnalogConverter (DAC), a frequency uplink converter, and the like.

A signal processing process for a receive signal in the wireless devicemay be configured in the reverse of the signal processing process (10100to 10600) of FIG. 25. For example, the wireless device (e.g., 1000 or2000 of FIG. 24) may receive the radio signal from the outside throughthe antenna port/transceiver. The received radio signal may betransformed into a baseband signal through a signal reconstructer. Tothis end, the signal reconstructer may include a frequency downlinkconverter, an analog-to-digital converter (ADC), a CP remover, and aFast Fourier Transform (FFT) module. Thereafter, the baseband signal maybe reconstructed into the codeword through a resource de-mapper process,a postcoding process, a demodulation process, and a de-scramblingprocess. The codeword may be reconstructed into an original informationblock via decoding. Accordingly, a signal processing circuit (notillustrated) for the receive signal may include a signal reconstructer,a resource demapper, a postcoder, a demodulator, a descrambler, and adecoder.

Utilization Example of Wireless Device to which Present Disclosure isApplied

FIG. 30 illustrates another example of a wireless device applied to thepresent disclosure.

The wireless device may be implemented as various types according to ause example/service (see FIG. 27). Referring to FIG. 30, wirelessdevices 1000 and 2000 may correspond to the wireless devices 1000 and2000 of FIG. 29 and may be constituted by various elements, components,units, and/or modules. For example, the wireless devices 1000 and 2000may include a communication unit 1100, a control unit 1200, and a memoryunit 1300, and an additional element 1400. The communication unit mayinclude a communication circuit 1120 and a transceiver(s) 1140. Forexample, the communication circuit 1120 may include one or moreprocessors 1020 and 2020 and/or one or more memories 1040 and 2040 ofFIG. 22. For example, the transceiver(s) 1140 may include one or moretransceivers 1060 and 2060 and/or one or more antennas 1080 and 2080 ofFIG. 22. The control unit 1200 is electrically connected to thecommunication unit 1100, the memory unit 1300, and the additionalelement 1400 and controls an overall operation of the wireless device.For example, the control unit 1200 may an electrical/mechanicaloperation of the wireless device based on aprogram/code/instruction/information stored in the memory unit 1300.Further, the control unit 1200 may transmit the information stored inthe memory unit 1300 to the outside (e.g., other communication devices)through the communication unit 1100 via a wireless/wired interface orstore information received from the outside (e.g., other communicationdevices) through the wireless/wired interface through the communicationunit 1100.

The additional element 1400 may be variously configured according to thetype of wireless device. For example, the additional element 1400 mayinclude at least one of a power unit/battery, an input/output (I/O)unit, a driving unit, and a computing unit. Although not limitedthereto, the wireless device may be implemented as a form such as therobot 1000 a of FIG. 27, the vehicles 1000 b-1 and 1000 b-2 of FIG. 27,the XR device 1000 c of FIG. 23, the portable device 100 d of FIG. 27,the home appliance 1000 e of FIG. 27, the IoT device 1000 f of FIG. 27,a digital broadcasting terminal, a hologram device, a public safetydevice, an MTC device, a medical device, a fintech device (or financialdevice), a security device, a climate/environment device, an AIserver/device 4000 of FIG. 27, the BS 2000 of FIG. 27, a network node,etc. The wireless device may be movable or may be used at a fixed placeaccording to a use example/service.

In FIG. 30, all of various elements, components, units, and/or modulesin the wireless devices 1000 and 2000 may be interconnected through thewired interface or at least may be wirelessly connected through thecommunication unit 1100. For example, the control unit 1200 and thecommunication 110 in the wireless devices 1000 and 2000 may be wiredlyconnected and the control unit 1200 and the first unit (e.g., 1300 or1400) may be wirelessly connected through the communication unit 1100.Further, each element, component, unit, and/or module in the wirelessdevices 1000 and 2000 may further include one or more elements. Forexample, the control unit 1200 may be constituted by one or moreprocessor sets. For example, the control unit 1200 may be configured aset of a communication control processor, an application processor, anelectronic control unit (ECU), a graphic processing processor, a memorycontrol processor, etc. As another example, the memory 1300 may beconfigured as a random access memory (RAM), a dynamic RAM (DRAM), a readonly memory (ROM), a flash memory, a volatile memory, a non-volatilememory, and/or combinations thereof.

FIG. 31 illustrates a portable device applied to the present disclosure.

The portable device may include a smart phone, a smart pad, a wearabledevice (e.g., a smart watch, a smart glass), and a portable computer(e.g., a notebook, etc.). The portable device may be referred to as aMobile Station (MS), a user terminal (UT), a Mobile Subscriber Station(MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or aWireless terminal (WT).

Referring to FIG. 31, a portable device 1000 may include an antenna unit1080, a communication unit 1100, a control unit 1200, a memory unit1300, a power supply unit 1400 a, an interface unit 1400 b, and aninput/output unit 1400 c. The antenna unit 1080 may be configured as apart of the communication unit 1100. The blocks 1100 to 1300/1400 a to1400 c correspond to the blocks 1100 to 1300/1400 of FIG. 30,respectively.

The communication unit 1100 may transmit/receive a signal (e.g., data, acontrol signal, etc.) to/from another wireless device and BSs. Thecontrol unit 1200 may perform various operations by controllingcomponents of the portable device 1000. The control unit 1200 mayinclude an Application Processor (AP). The memory unit 1300 may storedata/parameters/programs/codes/instructions required for driving theportable device 1000. Further, the memory unit 1300 may storeinput/output data/information, etc. The power supply unit 1,400 a maysupply power to the portable device 1000 and include a wired/wirelesscharging circuit, a battery, and the like. The interface unit 1400 b maysupport a connection between the portable device 1000 and anotherexternal device. The interface unit 1400 b may include various ports(e.g., an audio input/output port, a video input/output port) for theconnection with the external device. The input/output unit 1400 c mayreceive or output a video information/signal, an audioinformation/signal, data, and/or information input from a user. Theinput/output unit 1400 c may include a camera, a microphone, a userinput unit, a display unit 1400 d, a speaker, and/or a haptic module.

As one example, in the case of data communication, the input/output unit1400 c may acquire information/signal (e.g., touch, text, voice, image,and video) input from the user and the acquired information/signal maybe stored in the memory unit 1300. The communication unit 1100 maytransform the information/signal stored in the memory into the radiosignal and directly transmit the radio signal to another wireless deviceor transmit the radio signal to the BS. Further, the communication unit1100 may receive the radio signal from another wireless device or BS andthen reconstruct the received radio signal into originalinformation/signal. The reconstructed information/signal may be storedin the memory unit 1300 and then output in various forms (e.g., text,voice, image, video, haptic) through the input/output unit 1400 c.

In the embodiments described above, the components and the features ofthe present disclosure are combined in a predetermined form. Eachcomponent or feature should be considered as an option unless otherwiseexpressly stated. Each component or feature may be implemented not to beassociated with other components or features. Further, the embodiment ofthe present disclosure may be configured by associating some componentsand/or features. The order of the operations described in theembodiments of the present disclosure may be changed. Some components orfeatures of any embodiment may be included in another embodiment orreplaced with the component and the feature corresponding to anotherembodiment. It is apparent that the claims that are not expressly citedin the claims are combined to form an embodiment or be included in a newclaim by an amendment after the application.

The embodiments of the present disclosure may be implemented byhardware, firmware, software, or combinations thereof. In the case ofimplementation by hardware, according to hardware implementation, theexemplary embodiment described herein may be implemented by using one ormore application specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,and the like.

In the case of implementation by firmware or software, the embodiment ofthe present disclosure may be implemented in the form of a module, aprocedure, a function, and the like to perform the functions oroperations described above. A software code may be stored in the memoryand executed by the processor. The memory may be positioned inside oroutside the processor and may transmit and receive data to/from theprocessor by already various means.

It is apparent to those skilled in the art that the present disclosuremay be embodied in other specific forms without departing from essentialcharacteristics of the present disclosure. Accordingly, theaforementioned detailed description should not be construed asrestrictive in all terms and should be exemplarily considered. The scopeof the present disclosure should be determined by rational construing ofthe appended claims and all modifications within an equivalent scope ofthe present disclosure are included in the scope of the presentdisclosure.

INDUSTRIAL APPLICABILITY

In the wireless communication system supporting the MTC of the presentdisclosure, the method for transmitting/receiving the emergencyinformation is described primarily with various wireless communicationsystems such as a 5G system, etc., in addition to an example applied toa 3GPP LTE/LTE-A system.

1. A method of receiving, by a user equipment (UE), emergencyinformation in a wireless communication system supporting Machine TypeCommunication (MTC), the method comprising: receiving, from a basestation (BS), a System Information Block (SIB) including schedulinginformation for the emergency information; receiving, from the BS,configuration information related to a common search space; receiving,from the BS, first downlink control information (DCI) that is scrambledby a system information-radio network temporary identifier (SI-RNTI),for an emergency information indication, in the common search space; andreceiving, from the BS, the emergency information based on the first DCIand the scheduling information, wherein the first DCI has the same DCIformat 6-1A as a second DCI, wherein the first DCI has the same size asthe second DCI that is scrambled by a cell-RNTI (C-RNTI), which ismapped to a common search space. 2-3. (canceled)
 4. The method of claim1, wherein, the UE is a UE which operates in Coverage Enhancement (CE)mode A.
 5. The method of claim 1, wherein a common search space is aType0-MTC Physical Downlink Control Channel (MPDCCH) common searchspace.
 6. The method of claim 1, further comprising: receiving, from theBS, a Master Information Block (MIB) including scheduling informationfor the SIB.
 7. (canceled)
 8. The method of claim 1, wherein the firstDCI is received through an MTC Physical Downlink Control Channel(PDCCH).
 9. The method of claim 1, wherein the UE operates in an RRCconnection state.
 10. A user equipment (UE) configured to receiveemergency information in a wireless communication system supportingMachine Type Communication (MTC), the UE comprising: at least onetransceiver; at least one processor; and at least one memoryfunctionally connected to the at least one processor and storinginstructions for performing operations, wherein the operationscomprising: receiving, from a base station (BS), a system informationblock (SIB) including scheduling information for the emergencyinformation; receiving, from the BS, configuration information relatedto a common search space; receiving, from the BS, first downlink controlinformation (DCI) that is scrambled by a system information-radionetwork temporary identifier (SI-RNTI), for an emergency informationindication, in the common search space; and receiving, from the BS, theemergency information based on the first DCI and the schedulinginformation, wherein the first DCI has the same DCI format 6-1A as asecond DCI, wherein the first DCI has the same size as the second DCIthat is scrambled by a cell-RNTI (C-RNTI), which is mapped to a commonsearch space. 11-21. (canceled)
 22. A computer-readable storage mediumstoring at least one instruction which, when executed by at least oneprocessor, causes the at least one processor to control: receive, from abase station (BS), a System Information Block (SIB) including schedulinginformation for emergency information, receive, from the BS,configuration information related to a common search space, receive,from the BS, first downlink control information (DCI) that is scrambledby a system information-radio network temporary identifier (SI-RNTI),for an emergency information indication, in the common search space, andreceive, from the BS, the emergency information based on the first DCIand the scheduling information, wherein the first DCI has the same DCIformat 6-1A as a second DCI, wherein the first DCI has the same size asthe second DCI that is scrambled by a cell-RNTI (C-RNTI), which ismapped to a common search space.